"B"结构 Be＋表语（名词、形容词）＋其他. Be quiet,boys and girls!

同学们，请安静！ "L"结构 Let＋宾语＋（not）动词原形＋其他. Let's go to the washroom.

咱们去洗手间吧。 "Ｄ"结构 Don't ＋动词原形＋其他. Don't put them here.

不要把它们放在这儿。 【活学活用】 17.1）-I wonder if I could possibly use your car for tonight?

- ________.I'm not using it anyhow.

A.Sure,go ahead B.I don't know C.Yes,indeed D.I don't care

2）-I'm thinking of the test tomorrow.I'm afraid I can't pass this time.

-_______!I'm sure you'll make it.

A.Go ahead B.Good luck C.No problem D.Cheer up

3）ry not to start every sentence with "the". _______the beginning of your sentences.

A.Vary　　　　　　　B.Decorate C.FormD. Describe

4） -I'm sorry I'm late.I got held up in the traffic on my way here.

-_______.

A.Don't be late next time B.You should be blamed

C.It doesn't matter,I'm also late D.Never mind.Come and sit down

5）-I'm dead tired.I can't walk any farther,Jenny.

-_______,Tommy.You can do it!

A.No problem B.No hurry

C.Come on D.That's OK

6）_______and I'll get the work finished.

A.Have one more hour B.One more hour

C.Given one more hour D.If I have one more hour

答案与解析：

1)A　前者询问：不知我今晚是否能用一下你的车？后者在答语中说：我反正现在没用。由此推出他同意对方用他的车子。Ａ项，当然可以，用吧！合乎英语习惯。go ahead 是祈使句。

2)D　"我在想明天的测试，我担心这次不及格。""振作起来！我确信你能成功的。"cheer up 高兴起来，安慰、鼓励对方，例如：Cheer up!Our troubles will soon be over.振作起来!我们的困难很快就会过去。

3)A　题干中的第一个句子用否定形式，要求"不要用相同的the来开始每个句子"，第二个句子用肯定形式表达相同的意思，容易猜出要"变换句子的开头"。两句都是祈使句。

4)D　前者说自己迟到的原因是遇到交通阻塞，后者表示理解，说"没关系，请坐吧。"Come and sit down 是祈使句。

5)C　前者说我累了，不能往前走了，后者鼓励对方，"来，加油，你能行。"Come on是祈使句。

6)B　考查固定句型:祈使句＋and＋简单句。and的前面应该是祈使句，而不是从句或起从句作用的分词。One more hour是(You)Give me one more hour and I'll get the work finished.的省略形式。