Seventh grade science examination papers and answers

In the second semester of the 2006 school year, under the seventh grade of science, students studied the self-test unit and practiced the final examination paper (questionnaire). 1. Multiple choice questions: (3 points for each question, 75 points for * * *) 1. As the picture shows, what kind of senses do blind people use when reading Braille? -A, B, C, C. Car A, accelerating forward B, moving at a constant speed C, decelerating forward D, standing still 3. Use a crowbar to pry the stone, as shown in the figure, the end of the crowbar is easier to hold than the middle of the crowbar; This process shows that the role of force is related to which of the following factors:-. -So which of the following phenomena can't happen-() A, the car standing on the flat road can't start B, we can't write with a pen C, the people standing on the ground have no pressure on the ground D, we can push the train 6 with one finger. Just finished learning Erli. For this reason, four students in the class also had an argument. Which of their views do you think are correct? -() A, A: The gravity of the book and the support of the desktop to the book are a pair of balance forces B, B: The support of the desktop to the book and the pressure of the book to the desktop are a pair of balance forces C, C: The gravity of the book and the pressure of the book to the desktop are a pair of balance forces D, D: The book is unbalanced. Where contour lines overlap, a stands for-a, peak b, cliff c, ridge d and valley 8. Seen from the plane mirror. Then the actual number of this signboard is-() a,11018b, 8 10-65438+. 0 1 1-8 109. In the production of bonsai, in order to make plants flourish, the tops of plants in the pot are often cut off. In order to make which parts develop better, A, terminal bud B, lateral bud C, root D and flower 10. In a field activity, if you are alive, the measures and reasons you should take at this time are-. C, the old man has no pulse and respiratory arrest, has died, and does not need to call for help. D, although his pulse and breathing have stopped, but can't judge that he is dead, should immediately call for help. 1 1. The first cell of the next generation of plants is. Egg 12. As shown on the right, it shows the relationship between distance and time in the process of linear motion of an object, where A, B, C and D are four equal time intervals. In which time interval is the average speed of the object the largest? - () A，A，B，B，C，C，D，D， 13。 Spring blossoms. Little bees are flying around among the flowers, and their feet are covered with thick pollen. Bee behavior, () A, fertilization B, seed germination C, pollination D, flowering 14. The following are not the characteristics of adolescent development:-. The structure and function of the brain are developing rapidly. C, men began to nocturnal emission. D, women begin to have menstruation. 15. There are more seeds in the apple. Which of the following structures is related to this? The mistake that should be corrected in this experimental design is that there are two flowerpots. () The lighting conditions of flowerpots are not enough at 20℃ in the sun and 20℃ in the shade. There should be no water 17. Draw a convex lens in the box below:-. Can't do it-A, enlarge the reality. Inverted virtual image 19. The structure of pea seeds can develop into pea seedlings:-. The gravity map of this object is correct-() 2 1. Suppose that at noon from summer to Sunday, Xiao Li is in Tiananmen Square in Beijing and Xiao Xin is in Jinhua. The result is likely to be. In his hometown, we can observe-A, a direct phenomenon B, two direct phenomena C, direct phenomenon D every day, and there is no direct phenomenon 23. The phenomenon caused by the rotation of the earth is-. There are extreme days and nights on the earth. We usually refer to the areas with high altitude but relatively low altitude as-() A, Mountain B, Plateau C and Plateau C. Which of the following can be achieved -() A, in the east 12 after September 9, and then cross the date line to the west 12, and in the west 12 after September 9. Then, cross the date line to the D area of East 12, and cross the date line to the area of West 12 after September 8th of East 12. 2. Fill in the blanks: (2 points for each blank, ***30 points) 26. During the celebration, a helium balloon stood in the air with a slogan written on it. If the slogan quality is 3kg, (g = 10N/kg) 27. During a field trip, a classmate found that the distribution of rock strata on a cliff was obvious (as shown on the right), because the rocks there were formed under the action of internal forces. (Fill in "bending" or "breaking") 28. Now you can buy such an ornamental plant in the market: cut it out and put it in the water. After a few days, it will grow roots and then move into the soil to become a new plant. This way of reproduction is called reproduction. 29. When a beam of light obliquely shoots from the air to the water surface, the beam may reflect and phenomenon, and after entering the water, the propagation speed of light will (fill in "unchanged", "smaller" or "larger"). 30. As shown on the right, do an experiment in a vacuum. A beam of light shoots at the mirror from point S and passes through point A after reflection. When it passes through point A, find its speed as 3× 108m/s (fill in "greater than", "equal to" or "less than"). 3 1. A small wooden block floats on the water surface, and the gravity of the small wooden block is 3 Newton, so the buoyancy of water to it (fill in "greater than", "less than" or "equal to") is 3 Newton. 32. When a wooden box with a weight of 5000N is placed on the horizontal ground and pushed horizontally to the right 100N, it just moves in a straight line at a uniform speed. The friction force on the wooden box is n, and after several logs are placed under the wooden box, they are still pushed horizontally to the right at a uniform speed. At this time, the friction on the wooden box (fill in "increase", "decrease" or "unchanged") and the resultant force in the horizontal direction of the wooden box are n (please give two examples each). Boys: girls: 34. If a feather falls from the air in a straight line at a constant speed, the resistance is 0.0098 Newton, and the mass of this feather is grams. 35. In front of a high wall, Xiao Zhao clapped his hands, and he immediately heard the echo. If he is 0/70m away from the high wall/kloc-and the speed of sound is 340m/s, he will clap his hands for two seconds and then hear the echo. Iii. Analysis and explanation questions (2 points for each question, 30 points for * * *) 36. Answer the following questions according to the picture on the right. (1) The latitude of direct sunlight is called. (2) The solar terms of this day are. (3) What season is it in the northern hemisphere? The changing phenomenon of the length of day and night is. 37. The following is a passage from an imaginary composition written by a classmate. According to what you know, please write down three mistakes in the article: ... 65438+On February 22nd, I was reviewing my lessons, and suddenly all the friction and air resistance disappeared. I tiptoed lightly and people flew. Flying and flying, I came to the sky above the North Pole and saw some lovely polar bears playing in the snow under the sun. Flying up again, I looked down and found that the earth turned clockwise from east to west ... The error was: (1) (2) (3) 38. Liang Liang's brother is doing military service in Xinjiang. At eight o'clock in the evening, he reviewed his lessons in Jinhua and got ready for bed. At this time, his brother called from Xinjiang: "... it's only a little after six." Why do you go to bed so early? " We just finished eating! "Liangliang is confused: it's obviously past eight o'clock. Why did my brother say it was past six? Please help him explain why. (4 points) 39, "Ma Jia, red curtain, there is a white fat man living inside. "This is a riddle about peanuts. Please answer according to the following figure: (1) The future development of figure 2; (2) People's practical peanut oil mainly comes from the map (fill in the serial number); (3) 1, 2, 3 and 4 in the picture together are the "white fat man" in the riddle, which is called the larva of a new plant. 40. In the figure below, A, B and C are three contour topographic maps, while D, E and F are actual topographic maps (the shaded part indicates mountains or highlands). Please use short lines to correspond one to one: 4. Experiment and exploration: (*** 15) 4 1. For example, in Figures A and B on the right, the two slopes are the same and flat. According to the above experimental phenomena, please answer: ① The reason why the car stops after moving a certain distance on the plane is: (2 points) ② The purpose of this experiment is. (2 points) ③ In the above experiment, if the plane is made of ideal and smooth material, when the car slides down the inclined plane, the movement of the car on the plane will be. (2 points) 42. Objects fall from the air faster or slower. Some people say that the speed at which an object falls is related to its mass. Objects with large mass fall fast, while those with small mass fall slowly. What other factors do you think may be related to the falling speed? (Write at least two) (2 points) Next, let's study the relationship between the falling speed and the quality of an object: (1) Ask the question: Is the falling speed of an object related to the quality? (2) Establish a hypothesis that objects with large mass fall faster than those with small mass; (3) Experimental verification and data collection: (Xiaoming and Jason Chung do experiments separately) Xiaoming takes an object with his left hand and falls on the roof together ... (a) The variables to be kept constant in the experiment are: (2 points) The variables to be kept constant are: (1 minute) (b). The methods used in this experiment are as follows: (2 points) (4) Analyze the data and draw a conclusion: Xiaoming repeated the experiment for 65,438+00 times and drew a line chart (two curves represent two objects respectively). From the overall analysis of the diagram, we can draw the following conclusions: (2 points) Jason Chung did not do an experiment, but conceived a simple thinking experiment: set a heavy object and a light object to fall at the same time. If you put two objects together, B will be heavier than any single object, and the falling time should be shorter than any single object. Are these two conclusions contradictory? (1) From Xiao Zhong's thought experiment, we draw a conclusion (1) In the second semester of the 2006 school year, students learned the self-test unit exercise (final examination paper) for the seventh grade of science. Multiple choice questions:1-5.bcccc6-10.abbbd11-5.adaac16-20.acdbb21-20. 34. 1 35. 1 3. Analyze and explain the question 36. (1) Tropic of Cancer (2) Summer solstice (3) Summer days are long and nights are short. (1) I stood on tiptoe and people flew. (2) When I came to the North Pole, I saw some lovely polar bears playing in the snow under the sun. (3) Looking down, we find that the earth rotates clockwise from east to west. 38. Xinjiang and Jinhua are located in different time zones, so their time zones are different. 39.( 1) Stem and leaf (2) 1 (3) embryo 40. B-D air force one C-E 4. Experiment and inquiry: 465438+. 42. Volume shape (reasonable) (a) Shape and volume should be of the same mass (b) The same distance is faster than time, and whoever has less time is faster (4) The falling speed of an object has nothing to do with the mass, but the falling speed of an object has nothing to do with the mass.