Among the following solar terms or months, () A. Early July B. Summer solstice C. Winter solstice d. 65438+ 10 month.

A, early July is located near the perihelion, and the revolution speed is the slowest, so it is correct.

B, from summer to the sun, the sun shines directly on the Tropic of Cancer, and the speed of the earth's revolution is slow, which does not meet the meaning of the question.

C from winter to the sun, the sun shines directly on the tropic of Capricorn, and the speed of the earth's revolution is faster, which does not meet the meaning of the question.

D, 65438+1At the beginning of October, the earth was located near the perihelion, and its revolution speed was the fastest, which did not meet the meaning of the question.

Therefore, choose: a.

The revolution of the earth is a periodic circular motion, so the revolution speed of the earth includes angular velocity and linear velocity. If the sidereal year is used as the period of the earth's revolution, then the average angular velocity of the earth's revolution is 360 degrees per year, that is, after 365.2564 days, the earth will revolve 360 degrees, that is, about 0.986 degrees per day, that is, about 59' 8 "per day.

The total length of the earth's orbit is 940,000,000 kilometers, so the average linear speed of the earth's revolution is 940 million kilometers per year, that is, after 3,652,564 days, the earth revolves 940 million kilometers, that is, 29.8 kilometers per second, about 30 kilometers per second (linear speed = 940,000,000 kilometers /365 days = 940,000,000)