Choose the best topic sentence from the four options below. Write the corresponding letter of your choice on the answer sheet.

Choose the best topic sentence from the four options below. Write the corresponding letter of your choice on the answer sheet.

A.We human beings have done quite well in exploring the solar system.

B.The satellite has sent us a lot of valuable pictures of Mars and Saturn.

C.We have progressed from light planes to the landing of men on the moon.

D.Space crafts have landed on Mars and photographed Saturn at close range.

正确答案是A