Read the schematic diagram of the earth's revolution and complete the following questions: (1) Write the names of the four solar terms in the diagram A _ _ _ _ _ _ _ _ _ _ _ B _ _ _ _ _ _ _ _ C _ _ _

Read the schematic diagram of the earth's revolution and complete the following questions: (1) Write the names of the four solar terms in the diagram A _ _ _ _ _ _ _ _ _ _ _ B _ _ _ _ _ _ _ _ C _ _ _ _ _ D _ _ _ _ _ _ _ (2). (1) According to the map, A is the winter solstice, B is the summer solstice, C is the vernal equinox, and D is the autumn equinox;

(2) The revolution direction of the earth is from west to east;

(3) When the earth revolves to BD section, the direct point of the sun is between the Tropic of Cancer and the equator, in the northern hemisphere;

(4) When the earth revolves to A, there will be polar night in the Arctic Circle, and the length of day and night in the northern hemisphere will be different.

Therefore, the answer is: (1) winter solstice; Summer solstice; Vernal equinox; Vernal equinox; (2) As shown:

(3) the north; (4) The days are short and the nights are long.