C.The advantages of rockets.

D.The invention of rockets.

答案　1.C　2.C　3.C　4.B

1.brief adj.简短的；简洁的n.摘要；大纲

His book A Brief History of Time was published in 1988 and is still a bestseller.(教材P37)

他的著作《时间简史》于1988年发表，直到现在还是一本畅销书。

(1)in brief　　　总之；简短地

to be brief 简单地说(用作插入语)

(2)briefly adv. 简要地，扼要地

①Make sure that your speech is brief and to the point，so that the audience will not get bored.

确保你的演讲简短而且切题，这样听众不会感到厌烦。

②Give your reason in brief or I won't support you.

简单说明你的理由，否则我不会支持你。

③To__be__brief，she was happy with that result.

简单地说，她对那个结果感到满意。

④Would you please briefly(brief) introduce yourself?

请你做个简单的自我介绍，好吗？

[温馨提示] 表示"总之"的短语还有：in short；in a word；in a nutshell。

2.escape v.逃脱；逃避；被遗忘n.逃脱

The Chinese discovered that the gas escaping from the tube could lift it into the air.(教材P39)

中国人发现从竹筒里散失的气体能将竹筒发射到空中。

(1)make one's escape 　　逃跑

have a narrow escape 九死一生

(2)escape (doing)sth 逃脱(做)某事