A、The moon. B、Other planets. C、Both A and B D、Neither A nor B AWhich planet have some people reached?

Of all the stars the sun is the nearest to the earth. Millions of other stars are even bigger and brighter than the sun. They look small only because they are much farther away. You can’t see them in the daytime. But if you go out at night, you’ll be able to see thousands of them.
    The earth is one of the sun’s planets, and the moon is one of the earth’s planets, and men have visited it already. No man has traveled farther than the moon, but spaceships without people have reached other planets.
    Many countries have sent up man-made satellites to circle the earth. With their help, people have done much research in many fields of science. Some countries have sent up man-made satellites to send and receive TV programs. This has helped the people of China and ether countries to understand each other better.