根据提示补全下列教材原句

　　1．Last month I was_lucky_enough_to have a chance to make a trip into space with my friend Li Yanping，an astronomer.

　　我的朋友李彦平是一位宇航员。上个月我有幸有机会同他一道去太空旅行。

　　2．When we get closer to the moon，we shall feel its gravity pulling us，but it will not be as_strong_a_pull_as the earth's.

　　当更接近月球时，我们就会感到月球的引力在拉我们。但是，月球的引力不像地球的引力那么大。

　　3．But when I tried to step forward，I found I was carried twice_as_far_as on the earth and fell over.

　　但当我试着向前迈步的时候，我发觉我被送出去很远，步子的跨度竟是在地球上的两倍，因而我摔倒了。

　　4．"Oh dear，"I cried，"walking does need a bit of practice now_that gravity has changed."

　　我大声说："重力改变了，看来走路也的确需要练一练了。"

　　　阅读P30－P31教材课文，并从四个选项中选择最佳答案

　　1．The passage mainly talks about________.

　　A．what the moon is

　　B．my visit to the moon

　　C．the differences between the earth and the moon

　　D．Li Yanping，my friend，who is an astronaut

　　2．When we were going up，we felt________.

　　A．we were pressed against our seats

　　B．we were lighter than we were on the earth

　　C．as if we were flying

D．the rocket was shaking strongly