A．an introduction of the moon

　　B．the gravity that I felt on my way to the moon

　　C．my visit to the moon

　　D．my friend Li Yanping，an astronomer

　　2．From the text，we know that the force of the gravity would change ______ times.

　　A．2　　　　B．3

　　C．4 D．5

　　3．When or where did the author feel strongest of the gravity of the earth?

　　A．On the moon.

　　B．On the half way to the moon.

　　C．At the very beginning.

　　D．On their leaving from the moon.

　　4．What causes the author to feel that he becomes weightless on the moon?

　　A．Spaceship. B．Gravity.

　　C．His friend. D．Good feelings of the author.

参考答案

　　二、1．F　2．T　3．F　4．F　5．F

　　三、1．C　2．B　3．C　4．B