1. as, which引導(dǎo)非限制性定語從句,先行詞可以是整個(gè)主句或主句的一部分。
China is in Asia, as is known to us all.
正如我們都知道的那樣,中國在亞洲。
Light goes faster than sound , which is a fact.
光比聲跑得快,這是事實(shí)。
He said he had been to America , which isn't true.
他說他去過美國,這并不真實(shí)。
2. as, which在從句中作主語時(shí),其從句的謂語總是用第三人稱單數(shù)形式。
They are invited to dinner, which makes them very happy.
他們被邀請(qǐng)去進(jìn)餐,這使他們很高興。
3. as意為“正如”,引導(dǎo)的從句可放主句前,但which引導(dǎo)的從句不能放主句前。
As we all know , China is a third world country.
正如我們都知道的那樣,中國是個(gè)第三世界國家。
4. 從句是被動(dòng)語態(tài)時(shí),多用as引導(dǎo)從句。
China has sent up another man-made satellite, as was reported.
正如報(bào)道的那樣,中國又發(fā)射了一顆人造衛(wèi)星。
5. 從句謂語是know, see等時(shí),一般用as引導(dǎo)從句。
This man, as you know , is good for nothing.
正如你所知道的那樣,這個(gè)人一事無成。
6. as可用于the same ... as, such ... as結(jié)構(gòu)中,但which不能:
We're facing the same problem as we did years ago.
我們正面臨幾年前面對(duì)的相同問題。
They're just such persons as we trust.
他們就是我們信任的這類人。
7. which=and that意為“這一點(diǎn)”,當(dāng)從句是否定的,或者從句的謂語是系表結(jié)構(gòu),或者從句的賓語是復(fù)合結(jié)構(gòu)時(shí)多用which引導(dǎo)從句。
They said they were from France, which wasn't true.
他們說他們來自法國,這并不真實(shí)。
Last night I dreamed a spirit, which kept me awake all the night.
昨天夜里我夢(mèng)見鬼了,這使我一夜未眠。
8. as, which引導(dǎo)非限制性定語從句時(shí),不僅可以在定語從句中作主語,也可以作賓語或表語,但是不能省略。
As you told me , he is always very kind to everyone he works with.
正如你告訴我的那樣,他總是對(duì)一起工作的所有人都很和善。
He is a foreigner, which/as I know from his accent.
他是個(gè)外國人,這從他的口音我就知道。
He seemed a foreigner, as/which in fact he was.
他好像是個(gè)老外,其實(shí)他就是個(gè)老外。
專項(xiàng)練習(xí)
1. He must be from Africa, _______ can be seen from his skin.
A. that
B. as
C. it
D. what
2. They have decided to stay at home, _______ I think, _______ a wise choice.
A. which; are
B. which; is
C. that; are
D. that; is
3. William became the first American woman to win three Olympic gold medals in track, _______ made her mother very happy.
A. it
B. that
C. which
D. this
4. _______ everybody knows, he is very good at speaking English.
A. Which
B. That
C. Who
D. As
5. She heard a terrible noise, _______ brought her heart into her mouth.
A. it
B. which
C. this
D. that
6. The weather turned out to be very good, _______ was more than we could expect.
A. what
B. which
C. that
D. it
7. The number of the people present, _______ we had expected, was very large.
A. who
B. whom
C. that
D. as
8. That house, the doors _______ are painted white, is my grandpa's.
A. whose
B. which
C. of which
D. that
9. _______ has already been pointed out, grammar is not a set of dead rules.
A. As
B. It
C. That
D. Which
10. _______ is natural, he married Mary.
A. It
B. What
C. Which
D. As
答案速查 1-5 BBCDB 6—10 BDCAD