9　as的用法　Track09

 

（1）在as引導(dǎo)限定性定語(yǔ)從句時(shí)，只是用在一些固定的結(jié)構(gòu)中，即只能用在such，the same，as，so的后面。
a.He'11 repeat such points as are discussed in the book.
b. Such a student as works hard will be sure to succeed.
c.He tried to make as few mistakes as he could avoid.
d.He is not the same playboy as we knew.
e.The instrument is not such an instrument as I saw on the exhibition.
f.He is not such a man_________would leave his work half done.
A. who
B. whom
C. as
D. that
正確答案：C。
（2） as引導(dǎo)非限定性定語(yǔ)從句可位于句首，而which不能這樣用。
a.As is known, the whale is not fish but a mammal.
眾所周知，鯨不是魚(yú)類(lèi)，而是哺乳類(lèi)動(dòng)物。（as指的是the whale is not fish but a mammal整個(gè)句子。）
b. _________is known to the world, Mark Twain is a great American writer.
A. That
B. Which
C. As
D. It
正確答案：C。
c. _________might be expected, the response to the question was very mixed.
A. As
B. That
C. Which
D. What
正確答案：A。
（3） as和which都可引導(dǎo)非限定性定語(yǔ)從句，代替前面整個(gè)句子。
a.He married her, as/which was natural.
b.He was late for school, which/as is often the case.
但因?yàn)閍s引導(dǎo)的定語(yǔ)從句有“正好……”，“就像……”，“由……而知”的含義，所以，當(dāng)主句和從句在內(nèi)容上一致時(shí)，或者說(shuō)從句內(nèi)容是順著主句意思說(shuō)下來(lái)時(shí)，關(guān)系詞要用as。若主句和從句內(nèi)容上不一致，或從句的內(nèi)容對(duì)主句的內(nèi)容起反對(duì)、排斥、否定等消極的作用時(shí)，則多用which。試分析比較以下例句：

 
她很細(xì)心，這從她的工作中就可以看出來(lái)。