5．The author wants to explore other natural satellites like the moon.

　　答案：一、1.d　2.c　3.a　4.b

　　二、A.1.升空　2.接近　3.快；加油　4.玩得愉快

　　B．1.cheer up　2.now that　3.break out 　4.watch out

　　三、1.D　2.E　3.A　4.C　5.B

　　四、1.T　2.F　3.F　4.T　5.F

　　1．As the rocket rose into the air，we were pushed back into our seats because we were trying to escape the pull of the earth's gravity.

　　随着火箭的升空，由于我们在努力挣脱地球的引力，我们被向后推在座位上。

　　剖析：1)as the rocket rose into the air是时间状语从句。

　　2)because we were trying to escape the pull of the earth's gravity是原因状语从句。

　　考点：pull n．& vt. 拉(力)；拖；牵引力

　　He felt a slight pull at his coat.

　　他感觉上衣被轻拉了一下。

　　He gave a strong pull at the rope.他用力拉了拉绳子。

　　The moon's pull affects the tide on the earth.

　　月亮的引力影响地球上的潮汐。

　　She pulled his sleeve to get his attention.

　　她拉拉他的袖子以引起他的注意。

　　归纳：give a pull at sth 的含义是"拉......"。

　　1)反义词：push vt.推

　　He pushed open the library's door.

　　他推开了图书馆的门。

　　2)pull还有"穿上或脱下衣服、鞋袜"等的含义，如：

　　pull on表示"匆忙穿上"；pull off表示"匆忙脱下"。

　　He pulled on his coat and left quickly.

　　他匆忙穿上外套迅速离开了。

　　They pulled off their stockings.他们匆忙脱下长袜。

　　3)pull重点词组归纳：

　　pull through渡过难关；恢复健康

　　pull away脱身；离开

　　pull in (out) 进站；靠岸(出站；离岸)

　　pull down摧毁；推翻；拆除

　　pull up停下；拔起

　　The doctor is sure that he will pull through.

　　医生确信他将恢复健康。

　　She tried to pull away from the man.

　　她试图挣脱开那个男子。

　　Has the train pulled in (out)？火车进(出)站了吗？

The old house was pulled down.那座老房子被拆了。