(2)vt.to obey;to act in accordance with 遵守,顺从

我们必须遵守交通规则。We must _________

【keys】( observe the traffic rules).

(3)vt.to hold or celebrate 举行（仪式等）,庆祝（节日等）

你们国家的人庆祝圣诞节吗？

Do you _________ in your country?

【keys】(observe Christmas Day)

6.Only after her mother came to help her for the first few months was she allowed to begin her project.

她母亲头几个月来帮忙,这才使得她得以开展自己的计划。

Only+状语+部分倒装 "只有......才"

Exercise:

只有这样,我们才能学好英语。Only in this way _________

【keys】（can we learn English well）.

到那时我才意识到我的错误。Only then _________

【keys】（did I realize my mistakes）.

只有你了解我。Only you _________

【keys】（understand me）.

但Only+主语时不倒装

Multiple choice

1) I failed in the final examination last term and only then _________ the importance of studies.

A.I realized　　　　　　　　B.I had realized

C.had I realized　　　　　　 D.did I realize

　　【keys】（d）

2)It was _________ back home after the experiment.

A.not until midnight did he go B.until midnight that he didn't go

C.not until midnight that he went 　　D.until midnight when he didn't go

　　【keys】（c）

7.For forty years Jane Goodall has been helping the rest of the world understand and respect the life of these animals.