1. “连词+省略结构”通常可视为一种紧缩的状语从句，即认为是省略了从句的主语（与主句主语一致）和主语后的动词be。如：

Look out for car’s when (your are) crossing the street. 过街时注意车辆。

He acted as if (he was) certain of success. 他的举止就像一定会成功一样。

有时可视为省略了it is(其中的it并非主句主语)。如：

lf (it is) possible, please let me know by this evening. 如果可能的话，请在今晚以前告诉我。

Where (it is) necessary, improvements will be made. 哪儿需要，就在哪儿改进。

2. 并不是所有的状语从句都可以用以上办法来紧缩的，如原因从句就不能用这种办法来处理。

3. 与上面提到的省略结构相似且经常在高考中出现的还有if not…这一种形式。如：

His pronunciation, if not good, is at least tolerable. 他的发音如果说不算好，也还过得去。

If not today, tomorrow I’m sure you’ll get an answer. 如果今天得不到回信，明天准能得到。

Usually, if not always, we write “cannot” as one word. 我们即使不总是如此，也通常是把cannot作为一个词来写的。

This is one of the oldest buildings in town, if not the oldest. 这是城里最古老的房屋之一，如果不是最古老的话。

请看下现两道高考题：

1. We all know that, ____B___, the situation will get worse.

A. not if dealt carefully with      

B. if not carefully dealt with

C. if dealt not carefully with      

D. not if carefully dealt with

2. Though he started late, Mr. Guo played the piano as well as, if ___A___, Miss Liu.

A. not better than    

B. not better

C. no better than

D. better

【省略句短训】

01. When _________ the tunnel will be the longest in the world.

A. complete         B. completing       C. having completed  D. completed

02. Although _________ before the war, the engine is still in perfect order.

A. building           B. built                C. to be building       D. to have been built

03. Unless _________, this law will make life difficult for farmers.

A. to change        B. changing          C. changed              D. to be changed

04. Do not leave the building unless _________ to do so.

A. to instruct       B. instructed         C. being instructed   D. instructing

05. When _________ if he wanted anything else, he just shook his head.

A. asking             B. to ask              C. asked                 D. to be asked

06. If _________ for this post, you will be informed within a week.

A. accepting        B. to accept          C. accepted            D. to be accepted

07. These working conditions are unhealthy, _________ extremely dangerous.

A. if so               B. if not                C. so if                  D. not if

08. Her needs are just as important as yours, _________ so.

A. if not more      B. if more not        C. more not if        D. not if more

09. Where _________ necessary, improvements will be made.

A. they are           B. we are              C. are                   D. 不填

10. She hurried out of the room, as if _________ angry.

A. was                B. it was               C. got                   D. 不填

11. _________ paying by credit card, please pay in cash.

A. Unless             B. Until                 C. Since                D. Before

12. Although _________ ten years ago, the house still looks new.

A. building            B. built                 C. to build             D. having built

13. By 1977 things were beginning to improve, _________ quickly enough.

A. even if not         B. even not if       C. if not even          D. if even not

【参考答案】01—05 DBCBC  06—10 CBADD  11—13 ABA