332 as 意为 when／while（当……时）或 because／since（由于）

A as（= when／while）的用法的限制

这里 as 主要与表示动作或发展过程的动词连用，一般情况下它不与第168节中所列的动词连用，除如上面B3所示有发展之意时例外。在一般情况下它也不与 live，stay，remain 这类动词连用。

B as 与上述动词或同类动词连用时，一般均表示 because／since （由于）：

As he was tired… 相当于：

Because he was tired...

因为他太累了……

As he knew her well… 相当于：

Because he knew her well……

因为他了解她……

As it contains alcohd... 相当于：

Since/Because it contains alcohol……

因为它含有酒精……

As he lives near here… 相当于：

Since／Because he lives…

因为他住的地方离这儿很近……

C as 与多数动词连用时，可以是两种意思中的任一个意思：

As/While he shaved he thought about the coming interview．

他边刮胡子，边想着即将进行的面谈。

As／Because he shaved with a blunt razor he didn't make a very good job of it．

因为他用一把钝剃须刀刮胡子，所以刮得不好。

如果在这个问题上没有把握，最好用 while 或 because。

D as + 名词时意为 when/while（当……时）或 because/since（由于）：

As a student he had known great poverty．相当于：

When he was a student he had known great poverty．

他当学生时，经历过很贫困的生活。

As a student he gets/got in for half price．相当于：

Because he is／was a student be gets／got in...

由于是学生，他付半价就入场了。

As a married man，he has to think of his family．相当于：

Because／Since he is a married man...

作为一个有妇之夫，他必须考虑他的家庭。

as 在这里意为 when／while 时，后面常跟完成时态。

as 意为 because／since 时，后面可跟任一时态。