6．I don’t think you’ll be able to understand that ______ you are my age.

A. even　　　　　　　　　　　　 B. only when　　　　

C. as if　　　　　　　　 D. even when

5．She must have gone out early, _____ she had not shown up at breakfast.

A. because　　　　　　　　　 B. since　　　　　　　　

C. for　　　　　　　　　 D. therefore

4．If the way _____ you do the job is wrong, you will surely fail ____ good your idea may be.

A. how; however　　　　　 B. /; however　　　　

C.that; whatever　 D. in which; how

3．--Do you have any idea what Hank does all day?

　 --I know he speaks at least as much time watching TV as he __________.

A. does writing　　　　　　 B. writes　　　　　　　

C. is writing　　　　 D. does to write

2．The next moment, _____ she had time to realize what was happening, she was hit over the head.

A. when　　　　　　　　　　　 B. before　　　　　　　　　　

C. since　　　　　　　　 D. as

1．________, I couldn’t lift the box.

　　 A. As I might try　　　　　　　　　　　　　　　　　　 B. Try although I might

　　 C. As try I might　　　　　　　　　　　　　　　　　　 D. Try as I might

4．as if 和as though 从句可用省略形式，后接不定式、分词、形容词和介词。

⑾ The research is so designed that once ____ nothing can be done to change it.　　 (NMET2002)

A. begins　　　　　　　　　　 B. having begun　　　　　

C. beginning　　　　 D. begun

⑿ Generally speaking, _____ according to the directions, the drug has no side effect. (2003上海)

A. when taking　　　　　　 B. when taken　　　　　　

C. when to take　　　　　 D. when to be taken

[各个击破]

3． 以as，than引导的比较状语从句可全部或部分省去。

2．在虚拟条件状语从句中，如果从句中有had，should，were时，可省略if，用“had，should，were + 主语”形式。

1．当when，while，if，unless引导状语从句时，如果主从句的主语一致，且谓语部分由be动词构成(或者从句中有it is…)时，可省略主语和be动词(或省略it is)。