When the earth is located at point B, the solar terms in China are

(1) When the earth revolves to position A, the sun shines directly on the Tropic of Cancer, which coincides with the summer solstice in the northern hemisphere. When the earth revolves to position B, the sun shines directly on the equator, which coincides with the vernal equinox in the northern hemisphere, and the time is around March 2 1.

(2) When the earth revolves to position A, the sun shines directly on the Tropic of Cancer, which coincides with the summer solstice in the northern hemisphere, and the time is around June 22nd. At this time, there is extreme daylight in the Arctic, and extreme night in the Antarctic circle and its south.

(3) When the earth moves to B and D, the length of day and night in Zunyi is that the sun shines directly on the equator, and the length of day and night in Zunyi is equally divided; When the earth moves to a, the length of Zunyi day and night.

Therefore, the answer is: (1) summer solstice; March 2 1 or so; (2) Tropic of Cancer; Extreme day; (3) Equal division of day and night; The days are long and the nights are short.