Answer: (4 points) (1) Write the solar terms in the northern hemisphere when the earth revolves to positions A and B: A, B&; (=NationalBureauofStandards) ..

(1) summer solstice and winter solsti

Answer: (4 points) (1) Write the solar terms in the northern hemisphere when the earth revolves to positions A and B: A, B&; (=NationalBureauofStandards) ..

(1) summer solstice and winter solstice

(2) The polar night is at 2) 23.5 degrees north latitude (or the Tropic of Cancer)

Test analysis:

(1) During the earth's revolution, different positions of the earth's orbit are exposed to the sun in different ways, resulting in the changes of the four seasons on the earth. Among them, when the earth revolves to position A, the sun shines directly on the Tropic of Cancer, and the northern hemisphere is called the summer solstice. When the earth revolves to position B, the sun shines directly on the Tropic of Cancer, and the northern hemisphere is called the winter solstice.

(2) During the revolution of the earth, the latitude of direct sunlight is 23.5 N (or the Tropic of Cancer), and there are polar days in the Arctic Circle and polar nights in the Antarctic Circle.

Comments: During the revolution of the earth, different positions of the earth on the revolution orbit are irradiated by the sun differently, resulting in the changes of the four seasons. When the earth rotates to position A, the sun shines directly on the Tropic of Cancer, which is called summer solstice in the northern hemisphere. Around the summer solstice, the northern hemisphere gets more sunlight and heat, forming summer. When the earth revolves to position B, the sun shines directly on the tropic of Capricorn. This day is called the winter solstice in the northern hemisphere. During the period from winter to Sunday, the northern hemisphere gets less sunlight and heat, which forms winter. When the earth revolves to the position of vernal equinox and autumnal equinox, the sun shines directly at the equator. During this period, the ground gets less sunlight and more heat than summer, representing spring and autumn respectively. The seasons in the northern and southern hemispheres are opposite.