一、条件状语从句（重点）
关联词：if 、as……long……as、once
例如：If the study of law is beginning to establish itself as part and parcel of a general education, its aims and methods should appeal directly to journalism educators.
if引出条件状语从句（he study of law is beginning to establish itself as part and parcel of a general education,）。表示如果……（假如……）
Once a discovery claim becomes public,the discoverer receives intellectual credit.
once引出条件状语从句（a discovery claim becomes public）。表示一旦……
If you"re a physician,you can risk your patient"s suicide as long as you don"t intend their suicide.
if引出条件状语从句（you"re a physician,）。表示如果……
as long as 引出状语从句。表示但是……
二、让步状语从句（重点）
注意：让步状语从句不好理解，大家要注意哦!!表面上表示退一步，但是是为了进一步。即以退为进。
关联词：though、although、 even if、even though表示尽管……但是……
只是句子的一半，表面上表示让步，但是暗含转折。翻译成：尽管……/虽然……。后面省略了但是。
例如：
Although sadness also precedes tears,evidence suggests that emotions can flow from muscular responses.
although表示尽管……引出让步状语从句（sadness also precedes tears,）。
After all, it has an ad business too, which it says will comply with DNT requests,though it is still working out how.
though 引出让步状语从句（it is still working out how.）。
The defining term of intellingence in humans still seems to be the IQ score, even though IQ tests are not given as often as they used to be.
even though 引出让步状语从句（IQ tests are not given as often as they used to be）。
While the quality of legal journalism varies greatly,there is an undue reliance amongst many journalists on interpretations supplied to them by lawyers.
注意：这里是用while引出的让步状语从句（the quality of legal journalism varies greatly,），表示尽管...。
它在考试中用得比较少，简单了解就行了。
三、比较状语从句（不重要，能辨认出来就行了）
一个句子表示比较的对象，直接引到形容词/副词比较级。
例如：Rich economies are also less dependent on oil than they were , ...
than 引出比较状语从句（they were，）
In the general population today, at this genetic, environmental level, we"ve pretty much gone as far as we can go , ...
后一个as引出比较状语从句（we can go，）
四、方式状语从句（用得非常少）
用as 、 as if 引导。
例如：During most of his walking life he will take his code for granted, as the businessman takes his ethics.
as引出方式状语从句（ the businessman takes his ethics.）
Beethoven"s music tends to move from chaos to order as if order were an imperative of human existence.
as if 引出方式状语从句（order were an imperative of human existence.）表示似乎/好像...
状语从句中的连接词as一定要注意。太特别了，有四个意思：
1、“当......时候”引出时间状语从句。
2、“因为”引出原因状语从句。
3、“和......相比较”引出比较状语从句。
4、“按照......方式”“如同”引出方式状语从句。
5、“尽管”引出让步状语从句。
前两个最常用。
注意：如果用as引导的且后面是一个完整的陈述句，那么这个就是状语从句的连接词，至于是什么状语从句，可以根据上下文来判断是什么状语从句。如果as后面的句子缺成分，那么是引出的定语从句。
