When introducing the Zhaozhou Bridge in Chinese Stone Arch Bridges (ii). (iii) Why are the features not described in order from major to minor?

From major to minor Zhaozhou Bridge is not only unique in design, but also excellent in construction technology, with many creative:

(1) The site of the bridge was chosen more reasonably, so that the foundation of the bridge is stable and firm. Li Chun according to their own rich practical experience over the years, after rigorous thorough investigation, comparison, chose the ** river on both sides of the relatively straight place to build the bridge, the strata here is alluvial by the river, the surface of the strata is long after the water flow of the coarse sand layer, the following is fine stone, coarse stone, fine sand and clay layer. According to modern calculations, the strata here can withstand a pressure of 4.5 to 6.6 kilograms per square centimeter, while the pressure of Zhaozhou Bridge on the ground is 5 - 6 kilograms per square centimeter, which is able to meet the requirements of the bridge. After selecting the site of the bridge, the foundations and abutments were built on it, and since the construction of the bridge up to now, the foundation of the bridge has only sunk 5 centimeters, which means that the stratum here is very suitable for the construction of the bridge.

(2) The Zhaozhou Bridge was constructed in a novel way and is easy to repair. Li Chun on the ground, choose the nearby state county production of hard texture of green-gray sandstone as a bridge stone, in the stone arch masonry method, are used in the longitudinal (along the direction of the bridge) masonry method, that is, the entire bridge is composed of 28 independent of their respective arches along the width of the direction of the combination of juxtaposition and the arch thickness of 1.O3 meters, each voucher is independent of their own, individually, quite flexible, each voucher masonry completely together into a separate Coupon, after laying a coupon, move the weight of the "scaffolding", and then lay another neighboring arch. This masonry method has many advantages, it can save the production of "scaffolding" used in the wood, easy to move; at the same time, but also conducive to the maintenance of the bridge, an arch coupon of stone damage, as long as embedded in the new stone, local repair on the line, without having to adjust the entire bridge.

(3) in maintaining the stability of the bridge has taken many rigorous measures. In order to strengthen the lateral connection between the arches, so that the 28 arches form an organic whole, the connection is tight and solid, Li Chun has taken a series of technical measures. l) Each arch is wide and narrow on the lower part of the narrow, a little bit of the "closing" method, so that each arch is tilted inward, crowded against each other, to enhance its lateral connection, in order to prevent the arches of the stone to the outside to fall; In the width of the bridge is also used a small amount of "closing points" approach, that is, from the ends of the bridge to the top of the bridge gradually contraction of the width, from the widest 9.6 meters contraction to 9 meters, in order to strengthen the stability of the bridge. 2) in the main coupon uniformly along the direction of the width of the bridge set up five iron rods, through the 28 arches of the coupon, the ends of each tie rod has a semi-circular rod head exposed outside the stone, in order to clamp the 28 arches of the coupon, and to prevent the arch from falling out of the arch stone. The ends of each tie rod have semi-circular rod ends exposed outside the stone to clamp the 28 arch coupons and enhance their lateral connection. In the four small arches also have an iron tie rod to play the same role. 3) In the outside of a few arches on the stone and the two ends of the small arches covered with a layer of arch stone to protect the arch stone; in the protection of the arch stone on both sides of the hook stone 6, hooked to the main arch stone to make a solid connection. 4) In order to make the neighboring arches close together, on both sides of the outer coupon between the neighboring arches are worn to play the role of connecting "waist iron", the coupons between the "waist iron". ", the neighboring stones between the coupons are also in the arch back wearing a "waist iron", the arch stone chain. And the side of each piece of archstone are chiseled with fine diagonal lines to increase friction, strengthen the coupon lateral connection. These measures taken to make the whole bridge into a close whole, enhance the stability and reliability of the bridge.

(4) Zhaozhou Bridge abutment is unique. The abutment is the foundation of the whole bridge, must be able to withstand the main arch ring (the main body of the bridge) axis and to the force decomposition of the huge horizontal thrust and vertical pressure. Zhaozhou Bridge abutment has the following characteristics: l) low arch foot: arch foot in the riverbed under only half a meter or so; 2) shallow bridge foundation: the base of the bridge foundation in the foot of the arch of about 1.7 meters; 3) short abutment: from top to bottom, with gradual slight thickening of stone strips into a 5-meter-long, 6.7-meter-wide, 9.6-meter-high abutment. This is an economic and simple and practical bridge deck. In order to ensure the reliability of the bridge abutment, Li Chun has taken a number of corresponding measures to fix the foundation. In order to minimize the vertical displacement of the abutment (i.e., the subsidence caused by the vertical pressure of the main body of the bridge), Li Chun took the measure of driving many wooden piles into the side of the abutment to strengthen the foundation of the abutment; this method is often used in the construction of today's factories and bridges as well. In order to minimize the horizontal movement of the abutment (i.e., the backward movement of the abutment caused by the horizontal thrust of the main body of the bridge), Li Chun adopted the method of extending the abutment's back seat to counteract the effect of the horizontal thrust. In order to protect the bridge abutment and bridge foundation, Li Chun also set up a diamond wall along the river side, on the one hand, can prevent the erosion of water flow, on the other hand, the diamond wall and the bridge foundation and bridge abutment into a single unit, increasing the stability of the bridge abutment. By the above measures to ensure that the bridge has a strong abutment, improve the solidity of the bridge.

Lugou Bridge is also known as Lugou Bridge. In Fengtai District Lugouqiao Town Yongding River. It was built in the Jin Dynasty, nearly 810 years ago, and is the oldest surviving stone joint-arch bridge in Beijing. Yongding River was formerly known as Lugou River, and the bridge was named after Lugou.

The Lugou Bridge was designed according to the characteristics of the water flow of the Yongding River. All the bridge body with white stone, the total length of 21-2.2 meters, plus the two ends of the approach bridge, a total length of 266.5 meters. There are 11 arches, face width of 7.5 meters, there are 279 balustrades, the left side of the stone fence carved columns 140, the right side of the 141 columns, column height 1.4 meters, columns are carved crouching stone lions. The structure of the bridge and the piers, arches, all parts of the use of the waist iron solid, to strengthen the stone and the stone between the pull link. Piers are boat-shaped, facing the water for the tip of the water, and also placed in each tip of a triangular iron pillar, to resist spring ice and floods.

Lugou Bridge is also famous for its exquisite stone carvings. On both sides of the bridge there are 281 watchtowers with lotus flower seats carved at their heads and lotus leaf piers under the seats. Lookout pillar embedded in the middle of 279 pieces of railings, railings and the outside of the bridge surface are carved with vases, cloud patterns and other designs. On each pillar there are Jin, Yuan, Ming and Qing dynasties carved a different number of stone lions, most of which are original Ming and Qing Dynasties, Jin Dynasty has been very little, the Yuan Dynasty is not much. These stone lions crouch and lie down, a thousand postures, vivid and realistic, very rich in change, is the Lugou Bridge stone art boutique. Because of the bridge stone lion more than people can not count clearly, so Beijing circulated a hysteria "Lugou Bridge stone lion - can not count". 1961, cultural relics workers using the number of methods, *** inventory of stone lion 485. 1984, another verification, checking out the stone lion. In 1984, another verification, check the bridge stone lion as many as 489.

Lugou Bridge was built in Jin Dading 25 years (1189 years), Ming Zhengtong nine years (1444 years) rebuilt. It was destroyed in a flood during the Kangxi period of the Qing Dynasty and rebuilt in 1698. There is a Chinese alabaster stele with the inscription "Lugou Xiaoyue" by Qing Qianlong in the Stele Pavilion on the east side of the bridge, which is one of the Eight Scenes of Yanjing. Italian traveler Marco Polo in his travelogue, praised "it is the world's best, unique bridge".

July 7, 1937, the Lugou Bridge, the first anti-Japanese artillery, the war of national liberation began here. Lugou Bridge historical materials exhibition hall in July 7, 1981 in the bridge officially opened to the public. 1987 "Chinese People's Anti-Japanese War Memorial Museum" was officially completed. Memorial Hall steps there is a 4-meter-high art sculpture ---- "Lion Wake", symbolizing the Chinese people's heroic and unyielding national spirit

Respondent: ctdcy234 - trainee magician Level 3 11-27 20:59

Teaching Objectives

Moral Points: To understand the long history of the Chinese stone arch bridges and outstanding achievements, and to recognize the ancient working people's wisdom, inspire students to love the feelings of the motherland, dedication to science and the spirit of rigor and pragmatism.

Knowledge points: accumulation of "majestic, damaged, ancient and simple, respect, but also exquisite, ingenious" and other words, master the pronunciation and meaning of words; understand the great achievements of Chinese bridge construction, grasp the characteristics of stone arch bridge.

Ability points: to understand the object of description, grasp the characteristics of the object, the overall perception of the meaning of the text, to develop the ability to read the initial description of the text; to grasp the order of the description, to explore the skills of the author's description, to understand the author's way of thinking about the things, and to develop the ability of students to summarize; speculation on the language, to grasp the language of the text of the description of the language of the plain, accurate and thorough characteristics; preliminary understanding of the description of the text of the text of the description of the purpose of the narrative text and the use of language and the differences. The differences in the purpose of writing and the use of language between expository and narrative texts are recognized initially.

The focus of teaching

1. Guide students to grasp the characteristics of the stone arch bridge, grasp the characteristics of the method of description of things.

2. Taste the accuracy and rigor of the language of illustration.

Teaching Difficulties

To illustrate Chinese stone arch bridges with Zhaozhou Bridge and Lugou Bridge as the focus, to understand the author's order of illustration, and to explore the author's skill of illustration.

Teaching methods

1. Students read on their own and teachers pointing combination. Allow students to read and think for themselves, supplemented by the teacher's guidance, boring into vivid, dead into dynamic, to improve the efficiency of classroom teaching of illustrative texts.

2. Discussion method. Discussion method is a reflection of democratic thinking in classroom teaching, is conducive to stimulate students to take the initiative to participate in teaching, is conducive to the development of students' ability to comment and argue. Through discussion, students cooperate with each other in learning, dare to question, and constantly improve the ability to think, is conducive to the development of students' intelligence.

Teaching aids preparation

Multimedia, text materials.

Teaching Ideas

In teaching, we should seize the characteristics of the thing being described. This is the soul of the description of the text, only the characteristics are seized, clear, in order to make things clear; and the description of the method is selected for the description of the characteristics of the thing. In this article, the most prominent method of illustration is to give typical examples, which accounts for a large proportion of the text, the illustration of the role of significant, but also help students to understand the essence of the characteristics of the illustration of the text, therefore, the analysis of the examples should be put into an important position, the relationship between the examples and the essential characteristics of the thing to make sense of the relationship between the examples and the things.

Learning the language of expository texts can be accomplished by guiding students to analyze and compare the language, or it can be combined with skimming other methods of illustration (such as making analogies) and learning about grammar (analyzing sentence components).

Be careful not to make this a lesson about bridge knowledge.

Scheduled for two lessons.

Teaching Steps

The First Lesson

I. Introducing the New Lesson

The bridge is a bench enlarged--Bridge expert Mao Yisheng explains "bridge" in such a funny way. Mao Yisheng created the "Chinese stone arch bridge", to understand the stone arch bridge has a long history, beautiful form, the structure of the characteristics of the strong, feel the hard work of our working people and wisdom.

Two, check the preview, solve the problem.

1. note: arc arch bridge steep slope harmony drink stream well-proportioned piers Li Daoyuan

2. explain the meaning of the words and words: but wonderful harmony well-proportioned ancient and simple ingenious

The above two can be used to use multimedia to show a small or the use of projection display.

3. Discuss the topic.

(1) Analyze the phrase structure of "Chinese stone arch bridge".

Noun paratactic phrases.

Center word--"bridge"

Several determiners--"China" (the ), "stone" (of), "arch" (of)

Combined, it's "Chinese stone arch bridge".

(2) Interpretation of the word "arch".

What kind of shape is an arch? Please use the word "arch" to form a few words.

-"Arch", the original meaning is two hands together, up to show respect, such as "arch hand", can be grouped words: arch embrace, arch, arch, bridge arch, arch, etc., take the meaning of derivation "Surround", "arc". "Arch bridge", too.

4. Solve the problem: we are going to learn this text is a famous bridge expert Mao Yisheng wrote to introduce the bridge of science and technology to explain the text.

Please ask: What are the types of bridges?

-First of all, the categorization criteria should be clarified. According to the country, there are Chinese, foreign; according to building materials, there are stone village of wood, steel; according to the shape, there are flat, arch. This text with three qualifiers on the "bridge" to do a clear limit. So, what are the characteristics of this "Chinese stone arch bridge"? The author and how to introduce this feature to everyone, this is our study of this text to figure out two important questions.

Three, point to read

(a) the characteristics of the Chinese stone arch bridge.

In order to make things clear, explanatory texts pay special attention to the order of description, which we have some understanding in the first year of learning "the language of nature" and other texts. Now the students read quickly and take three minutes to find out what things each paragraph is about, and use a pen to mark them in your textbook as you read.

The teacher summarizes. Board:

Stone Arch Bridge: (1-2) Chinese Stone Arch Bridge: Ancient Condition (3-9) Chinese Stone Arch Bridge: Contemporary Developments (10)

1. Characteristics of Stone Arch Bridge.

Get one student to read aloud paragraphs 1 and 2 while the others identify the words that describe the characteristics of stone arch bridges.

The teacher summarizes. Board:

Appearance - earlier

Form - beautiful

Structure - strong

How does the author illustrate these characteristics? (Students' answers can be organized or the teacher can point them out, depending on the time)

--The myth compares a rainbow to a bridge, and the poet compares a bridge to a rainbow. The bridge and rainbow are compared to each other to illustrate both the shape and the beauty of the bridge. The analogy is meant to be illustrative, with praise, but the language is concise and moderately appropriate.

"Can be decades hundreds or even thousands of years of male across the river", both explain the stone arch bridge appeared earlier, but also that it is structurally strong.

The first paragraph explains that the stone arch bridge has a beautiful form, and the second paragraph explains that the stone arch bridge has a sturdy structure, reflecting the order of writing from the outside to the inside. The "not only ...... but ...... also" recursive relationship accurately reflects and emphasizes this point.

2. The characteristics of Chinese stone arch bridges.

Paragraph 3 begins to describe the Chinese stone arch bridge. Students draw out the characteristics of the Chinese stone arch bridge, see, the general characteristics of the stone arch bridge mentioned in the last two paragraphs, the Chinese stone arch bridge is not also there, and what is unique about the Chinese stone arch bridge?

The teacher summarizes. Board:

Long history - long history

Almost everywhere - many and wide

Various sizes and forms, and many of them are astonishing masterpieces - varied and outstanding

From time In terms of time, Chinese stone arch bridges lead the world in the history of bridges. According to: (a) "long" more emphasize the early time; (b) "travelers bridge" "may be the earliest recorded stone arch bridge". What about form and structure? In this paragraph, the Chinese stone arch bridges are recognized with "many of them are amazing masterpieces", and it shows that our stone arch bridges are "amazing" masterpieces among the bridges. In addition to this place, our Chinese stone arch bridge also has a large number, wide distribution, some grand, some small, colorful form of unique. It can be seen that our ancestors in this area for mankind to make outstanding contributions.

Zhaozhou Bridge and Lugou Bridge are the representatives of this amazing masterpiece. The author better illustrates the characteristics of Chinese stone arch bridges through the introduction of these two bridges.

3. Zhaozhou Bridge, a masterpiece of Chinese stone arch bridges.

The article introduces Zhaozhou Bridge in paragraphs 4 and 5. Mark the relevant statements in the reading to see what are the characteristics of Zhaozhou Bridge, to see which is the stone arch bridge **** have, which is Zhaozhou Bridge unique outstanding place?

The teacher summarizes. Board:

Zhaozhou Bridge is a world-famous ancient stone arch bridge, is an amazing masterpiece of Chinese stone arch bridge I. It has the general characteristics of stone arch bridges, for which the article first makes a general introduction in paragraph 4. "It has been more than 1,300 years by now" shows that it appeared early, "it has been used until now after it was built" "it still keeps its original appearance" shows that it is strong and beautiful. At the same time, Zhaozhou Bridge has its own unique characteristics, and indeed deserves to be called an amazing masterpiece.

Paragraph 5 of the bridge's length and width data, indicating that it is amazingly majestic. Then it points out that it is scientifically designed and technologically ingenious, which is the reason why Zhaozhou Bridge is outstanding from a general point of view. The following four aspects of the specific description of its scientific and ingenious. Students should note that each aspect not only introduces the characteristics, but also explains the principles of such design and construction. This is precisely the characteristic of an expository essay: to make explanations about things and their reasons.

①How could a "37.4-meter-long" arch, the largest in the world at the time, ensure easy transportation?

-The designers of the Zhaozhou Bridge broke the mold by making the bridge bow-shaped, with no steep slopes, making it easy for cars and horses to get on and off the bridge, which can be said to be ingenious indeed.

②such a bridge, but also a single-arch bridge, with more stone, on both sides of the bridge foundation will be a lot of pressure, how to do?

-- flood season, the river surges, the bridge will be violently impacted, how to do? Designers creative design, arch on the arch, not only two birds with one stone, and received a beautiful wondrous effect, not worthy of ingenuity.

3 bridge so long, so wide, how to ensure that it is strong? How to facilitate the construction?

-The designer's ingenuity, by twenty-eight arches into a curved cavern, it is a strange manufacture.

4 In addition to the structure, the form of Zhaozhou Bridge is also well-proportioned and beautiful, harmonizing with the surrounding scenery, and the artistic value is also monumental.

It is also worth noting that the author quoted the words of Zhang Jiazhen to explain the peculiar structure of the bridge, then quoted the words of Zhang River to explain the beautiful form of the bridge, and finally stated that Zhaozhou Bridge is the crystallization of the wisdom and strength of the working people of our country represented by Li Chun. First total, then divided and then total, the characteristics of Zhaozhou Bridge introduced clearly.

Four, class summary

The unique features of Zhaozhou Bridge strongly illustrate the characteristics of Chinese stone arch bridges. Zhaozhou Bridge is a one-arched stone bridge located on the Xiao River, next, the article cited the Yongding River on the multi-arched stone bridge Lugou Bridge, which confirms the number of stone arch bridges in China, the distribution of a wide variety of forms of characteristics.

Fifth, set homework

1. Think: Zhaozhou Bridge unique features and the characteristics of Chinese stone arch bridge what is the relationship?

2. Finish Exercises I and II (part of the Lugou Bridge as a pre-study, do not fill in the form first, but mark on the text.)

3. Pre-study and think about III, IV and V.

The second lesson

I. Learning from the past

1. Say the relationship between the unique features of Zhaozhou Bridge and the features of Chinese stone arch bridges.

2. State the characteristics of Lugou Bridge.

2. Introduce the new lesson

1. Another masterpiece of Chinese stone arch bridges--Lugou Bridge.

Lugou Bridge is another amazing masterpiece of China's stone arch bridges, has asked the students to do a preview, and now let's discuss what are the similarities and differences between Lugou Bridge and Zhaozhou Bridge.

--Location, over the Yongding River, which is a large river wider than the Xiao River.

--Time, later than Zhaozhou Bridge, but also more than 800 years ago, said a long history.

--The bridge is much longer and slightly narrower than Zhaozhou Bridge. The bridge is flatter. The biggest structural difference is that the Lugou Bridge is a joint-arch stone bridge, which relies on stone piers to join together as a whole to withstand flooding.

--It is also very beautiful, especially the stone lions on the headstones.

--Lugou Bridge is well known in China and abroad, and is a memorial site for the War of Resistance against Japan.

Summary, board:

Last lesson we summarized the characteristics of Chinese stone arch bridge, in addition to having the general characteristics of stone arch bridge: appeared earlier, structural solid, beautiful form of the characteristics of the bridge, but also only a long history, a large number of widely distributed, varied and outstanding more prominent features. The typical examples of Zhaozhou Bridge and Lugou Bridge are good proof of these characteristics. Among them, the article introduces most fully their outstanding: ingenious, peculiar and exquisite, because this aspect best illustrates the outstanding achievements of Chinese stone arch bridges in terms of structural solidity and beautiful form. How to choose examples and how to use them when illustrating things, this text provides us with good examples.

2. The reasons for the glorious achievements of Chinese stone arch bridges.

Read paragraph 9 aloud by name, other students listen and mark and summarize, how many reasons are there and what are they?

--There are three reasons: first, the diligence and wisdom of the working people; second, the design and construction of a good tradition ("material saving, clever structure, high strength," Zhaozhou Bridge, Lugou Bridge is an outstanding representative); and second, rich in a variety of building with the Secondly, it is rich in various kinds of stone materials for construction. The first of the three is the most important, because the people's hard work and wisdom, it is possible to utilize the rich stone, it is possible to carry forward the fine tradition.

3. The modern development of Chinese stone arch bridges.

Read paragraph 10 together. Think: What examples are given in this paragraph to illustrate the new development of Chinese stone arch bridges?

--Changhong Bridge, the world's longest one-arch stone bridge, the arch length of one hundred and twelve point five meters, three times as long as Zhaozhou Bridge. Double arch bridge, the only one in the world, the country made a total length of more than 200,000 meters, the longest hole one hundred and fifty meters. This reinforced concrete arch bridge inherited and developed the tradition of stone arch bridge.

This new development, new achievements, because of a new reason: the socialist system is incomparably superior.

4. The plain, accurate and strict language of the explanatory text.

Discuss the after-class exercises and the teacher summarizes.

This expository essay, with Zhaozhou Bridge and Lugou Bridge as examples, introduces Chinese stone arch bridges clearly, is inseparable from its excellent use of expository language. There are four aspects that students should experience and learn.

(1) The language is simple and concise, and the descriptions are measured.

This text is in the same genre as the Dictionary entry, but it only further explains the reason for this structure of the Lugou Bridge. This text is also descriptive, but in a very moderate way. For example, the first paragraph compares the bridge to a rainbow to illustrate the curved shape of the bridge, with praise implicit in its clarity.

The stone lions of the Lugou Bridge are described, reflecting the feelings, but they are not indulged in writing, but moderately closed. Speaking of Lugou Bridge is a war shrine only three sentences: a statement of the significance of commemoration, a statement of the time of the war, the nature of the war, a statement of the anti-aggression war of the jaws of the guide and the results of it, simple and concise.

(2) The use of illustrative methods, the purpose is clear.

The article in order to accurately and vividly explain things, often use a variety of methods of description. Students should pay attention to experience, no matter which method of description, the purpose is to introduce knowledge, explain the characteristics of things.

Quoting from an ancient text - "Zhang Jiazhen of the Tang Dynasty said that it was strangely made and 'one knows why'."

Listing figures - "Zhaozhou Bridge is very majestic, fifty point eighty-two meters long, nine point six meters wide at both ends, and slightly narrower in the middle, nine meters wide."

Using metaphors - "China's poets love to compare arch bridges to rainbows, saying that arch bridges are 'crouching rainbows' and 'flying rainbows', and arch bridges over water are described as 'a long rainbow lying on the waves'."

To describe - "The whole bridge structure is well-proportioned, and the surrounding scenery with a very harmonious; even the stone railing on the bridge slate is also carved in a rustic and beautiful."

Explaining - "Between every two stone arches there are stone masonry piers, which link the eleven stone arches into a whole. Since the arches are linked together, this bridge is called a 'joint-arch stone bridge'."

It is these plain, accurate and strict explanatory language that achieves the effect of saying and clarifying.

(3) Carefully pushed the words, to the point.

Some words are very precise and certain, such as the listed time, data, such as the limitations of certain time, degree; some words indicate an estimate. Either way, there is only one purpose: to state accurately; there is only one basis: to conform to reality.

For example, when it comes to the "Traveler's Bridge", before the "stone arch bridge", "may" (indicating an estimate) "has recorded " (made a qualification) "earliest" (in the estimation, after the qualification of the time to do a definite qualification) three qualifiers, explaining clearly. Another example is the description of the Zhaozhou Bridge with these two qualifiers: "caused and has been used until now" "the most ancient", of which the second qualifier explains the long history of the Zhaozhou Bridge, but it is accurate only under the qualification of the first qualifier. "China's stone arch bridges are found almost everywhere", "everywhere" reflects the "large number and wide distribution", but only under the qualification "almost But only under the qualification of "almost" is it realistic and accurate. The conclusion that "each stone arch is of different lengths" was made after verifying the lengths of eleven stone arches on the Lugou Bridge. A student asked Mao Yisheng about this matter, and Mao Yisheng replied by listing the lengths of the eleven stone arches, none of which was the same. Seemingly simple sentence, but reflects the language of expository essay accurate and rigorous. This aspect of the language of expository language requirements, in this text, especially in the use of determiners, gerunds and complements, students can pay attention to experience.

4. Pay attention to the order of words and phrases, well thought out.

The first form of writing, is the bridge to give a person's intuitive impression, is a perceptual understanding. The structure is strong, is a further understanding of the bridge, that is, rational understanding. Therefore the relationship between them is progressive rather than juxtaposition. "Not only ...... but also ......" reflects a rational order that cannot be deleted, nor can the order of what it links be reversed.

The small arch over the shoulder is the main feature of the first Zhaozhou Bridge, the most illustrative of Zhaozhou Bridge's ingenious and peculiar, and the arch circle is also seen in other arch bridges, than the small arch over the shoulder is relatively minor.

The first generalized Zhaozhou Bridge shape and design and construction features, and then divided into four points of specific instructions, the first total and then divided, giving a clear impression. Another example, explain the reasons for the glorious achievements of China's stone arch bridge, with "first", "second", "and then second", indicating that the sub-explanation, from people to things, from the main to the second, in a reasonable order, the Clearly labeled.

Three, classroom summary

In the students summed up on the basis of the teacher summarized:

1. This article describes the characteristics of the Chinese stone arch bridge, the history of the brilliant achievements and the development of the establishment of new China, praised the ingenuity of the working people of our country and the socialist system is superior.

2. This article takes Zhaozhou Bridge and Lugou Bridge as examples, specifies the characteristics of Chinese stone arch bridges, and analyzes the reasons for them and describes the development.

3. This article is excellent in the use of illustrative language: concise, plain, accurate and thorough. The language style is different from that of a narrative essay.

Four, assign homework

1. Please clarify the order of description of the text about Zhaozhou Bridge and Lugou Bridge.

2. According to the text and illustrations, draw a schematic diagram of Zhaozhou Bridge, labeled with the corresponding data.

3. Speculate on the language.

1) The stone arch bridge has a curved hole, just like a rainbow. Ancient myths say that the rainbow after the rain is "the bridge between heaven and earth", and through the rainbow you can go to heaven. Our poets love to compare the arch bridge to a rainbow ...... (Can the bolded words "stone arch bridge", "bridge" and "arch bridge" be replaced? replaced? Why?)

-Can't be interchanged. Because the text is about "stone arch bridges in China", the first sentence follows the title and uses the concept of "stone arch bridges". In ancient times, people could only recognize the world in the form of myths, saying that "the rainbow after the rain is the 'bridge in the sky on earth'", and here we can only use the word "bridge" to match the word "myth". The word "bridge" can only be used here in order to correspond to the word "myth". As for "comparing the arch bridge to a rainbow", it is closely related to the characteristic of "arch bridge" which has a curved hole.

②Stone arch bridges appeared relatively early in the history of the world's bridges. ("Comparison", remove the word okay?)

--"Comparatively early" to a lesser extent, this expression is more secure.

③The bridge is not only beautiful, but also sturdy. （

The bridge is not only beautiful, but also sturdy. Can the order of the words "strong structure" and "beautiful form" be adjusted?)

--"Not only" "and" can not be deleted, if deleted, the relationship between them becomes a juxtaposition. First say appearance, then say function, in line with people's cognitive logic. And for the bridge, its practical value is far more important than the form, so the two can not adjust the order.

4The "Traveler's Bridge" mentioned in the "Notes on the Water Classic" was built around 282 AD, and is probably the earliest stone arch bridge on record. (Can the bolded words be removed?)

--"About" and "may" are both uncertain and speculative. "Documented" adds reliability to the basis of the statement.

⑤ There are stone arch bridges almost everywhere in China. (Is it okay to drop "almost"?)

-"Almost" emphasizes the wide distribution of stone arch bridges, but it does not exclude the possibility that there are places where there are no stone arch bridges.

6 (Zhaozhou Bridge) has only one large arch, which is 37.4 meters long, and at that time could be considered the longest stone bridge in the world.

--"At that time" is qualified from the time, "can be counted" is qualified from the degree. This is more in line with the actual situation.

⑦A. Zhaozhou Bridge is very majestic, with a total length of 50.82 meters.B. Lugou Bridge is about 8 meters wide. (Compare and contrast the two sentences, what do you find?)

--The comparison of the two sentences can reveal the author's rigorous scientific attitude. A more than 50-meter-long Zhaozhou Bridge can be accurate to 0.01 meters, which is how accurate the description. "About" indicates that the width of the Lugou Bridge is not exactly 8 meters, which shows the author's realistic attitude to writing.

Students read the sentences aloud, think, experience, and communicate with each other. Teachers point out: the language of expository writing has the characteristics of accuracy and strictness. Summarizing the above example sentences, it can be found in this article: the use of figures is accurate; if there is no way to use accurate figures, the figures that indicate estimation will be used; for the meanings that are temporarily not sure, the language that indicates speculation will be used to express them; and the appropriate use of limiting words makes the expressed meanings tend to be accurate. Therefore, we study the language of the explanatory essay, the most important thing is to grasp the word "accurate".

Students will find examples of accurate and strict language and share them with the class.

●Activities and Explorations

1、Bull-dogging

(1) We live in the water town of Jiangnan, and bridges are everywhere. Some of the bridges you have traveled, maybe just "step stone" bridge, a wooden bridge, or may be a tall, strong reinforced concrete bridge, may have been some years, or may be newly constructed soon. In any case, they all have their own role, in the construction and building materials have their own characteristics, please observe them carefully, and understand, collect information about their construction, write a 500-word introductory text, in a certain order, introduce a familiar bridge.

Tips: the requirement to write a descriptive essay, do not spend more ink on the story about the bridge, the feelings of the bridge on the lyrical, the language should be concise and accurate.

(2) in the face of a wide range of overpasses, drivers, pedestrians are at a loss, try to write a "Driver's Guide" type of short essay on an overpass in your home city, about 400 words.

(3) to "my hometown of xxx bridge" as the title, write two different genres of articles: one written as a narrative, one written as an explanatory essay.

2, the future

(1) envision what the future of the bridge is like, draw, first group communication, and then each group elected a representative to report to the class.

Tips: the vision of the future bridge is built on the current bridge what are the shortcomings and defects based on the knowledge, so you can first discuss the various types of bridges, various uses of bridges now and what needs to be improved, and then think about what the future bridge is like.

(2) Collect information about famous bridges in ancient and modern China and abroad outside the classroom, and then categorize them from different perspectives (e.g., structure, function, building materials, etc.), and choose some characteristic bridges to build a small file for them.