高悬赏求5句英语的语言点,语法

高悬赏求5句英语的语言点,语法
1.Last month I was lucky enough to have a chance to make a trip into space with my friend Li Yanping,an astronomer.
2.Before we left,Li Yanping explained to me that the force of gravity would change three times on our journey and that the first change would be the most powerful.
3.I cheered up immediately and floated weightlessly around in our spaceship cabin watching the earth become smaller and the moon larger.
4."Oh dear," I cried,"walking does need a bit of practice now that gravity has changed."
5.We watched,amazed as fire broke out on the outside of the spaceship as the earth's gravity increased.求这五句话的语言点,语法,是什么从句等等.
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