Question

英语超难单选题求助!

7. _______it happens, there is always someone who will help her in secret .

A.When B.While C.Since D.As

答案是D.as引导定语从句,但是我们班很多同学都错选A,认为应该是时间状语从句. 请老师讲解一下,并介绍一下"as"的用法.as引导定语从句都有那些具体句型和用法,在句中做什么成分,和其他的定语从句的引导词之间有什么区别?

不胜感激!

Answer 1

如果主句谓语动词表示的是短暂动作，从句时间状语指一段时间，则when，while，as都可用
as和when可与非延续性动词连用，而while只能与延续性动词连用
as和when都可用来指一段时间，但as强调主句和从句表示的动作同时发生，而while强调主句表示的动作是在while从句的动作延续中发生的
She sang as she went along她边走边唱歌
She sang while she went along她走路时一直在唱歌

Answer 2

as在英语中是最活跃的词之一，它既可作副词、连词、介词，也可作关系代词。下面就as引导的各类从句 和惯用法，试作归纳，供学习时参考。
一、表示比较，意即“象……一样”。
1. Harry is unusally tall,as are his brothers.
哈利也象他的弟兄们一样，身材奇高。
2.Army and people are as inseparable as fish and water.
军民关系，亲如鱼水。
3.The work is not so easy as you imagine.
这工作不象你想象的那么容易。
二、表示方式、程度、情况。意即“按照、如同、象”。例如：
1.The number of deer ,mountain lions,and wild roses does not changemuch if people leave thi ngs as they are.
如果人们听其自然发展，鹿、美洲狮和野玫瑰的数量不会有很大的变化。
2.He writes about china as he sees it.
他照他亲眼看见的样子描述中国的情况。
3.We must serve the people whole-heartedly as comrade Lei Feng did.
我们要象雷锋同志一样全心全意为人民服务。
三、表示时间，意即“当……时候”，“一边……一边”“随着……”。
1.As time went on ,Einstein’theory proved to be correct.
随着时间的的推移，爱因斯坦的理论证明是正确的。
2.I read the book as I went along.
我边走边读。
3.As a young man,he was a storekeeper and postmaster.
年轻时，他当过店主和邮电局局长。
四、表示原因，意即“因为，即然”。
As he wasn’t ready in time,we went without him.
因他未能及时准备好，我们就去了，没有等他。
五、表示让步，这种从句有两个特点：1）语气比though（although）引起的从句强些。2）表语一般放 在本从句之首；如有可数名词单数，前面也不要冠词。
child as he is ,he can tell black from white.
尽管他是个孩子，但他能够分辨黑白。
Badly wounded as he was,he remained quite optimitic.
虽然他伤势严重，但他仍然十分乐观。
这种句型偶尔也表示原因。
He has made no progress at all ,lazy (fellow)as he,is.
因为他懒惰，所以毫无进步。
六、引导表语从句：
Things are not always as they appear.
事情不一定总是它们表现出来的那样。

七、引导定语从句。

1）as引导非限制性定语从句，常指主句所表达的整个事情，可置句首、句中、句末，常见 as we all know,as I see it 照我看来，as it appears to me 依我看来。
As we have seen,oceans cover more than 70 per cent of the earth.
正如我们所知道的，海洋占地球面积70％以上。

2）as引导限制性定语从句
From every corner of the island little people came to see the "Man Mountain~as they called Gulliver.
小人们从海岛的各个角落来看他们叫做‘人山’的格利佛。

3）as与 such,the same 连用，此时先行词是一个具体的名词，as在从句中可作主语、宾语或表语。
The book is written in such easy English as beginners can understand.
这本书是用初学者也能读懂的浅易英文写的。
She studies in the same department as I do.
他和我在同一个系统学习。

八、as还可以与其他词构成成语型的连词。
So(As)long as one inch of this deck remains above water,there is hope.
只要这船的甲板还有一英寸保持在水面上，就还有希望。
She has no experience in teaching as far as I know.
据我所知，她毫无教学经验。
此外so as to＋不定式表示结果、目的，意即“以至于”，“以便”。
He raised his voice so as to be heard
他提高嗓门，好让别人听到。
又as to可以引起各种从句。
You must remember to inform me as to whether we should do it.
这事究竟做不做，你要记得通知我。