备战2021年军队职称英语考试之重点语法精讲（8）

Make a mark wherever you have any questions.
We will go where the Party directs us.
目的状语从句：that，so that，in order that
注意：目的状语从句的谓语动词常与情态动词连用，否则可能是结果状语从句。不可置于句首。
结果状语从句：that，so that，so…that，such…that…
注意：so+形容词/副词+that从句；such+名词+that从句。
方式状语从句：as，as if（though）
I'll do as I am told to.
It looks as if it is going to rain.
比较状语从句：than，as
条件状语从句：if，unless，so（as）long as，in case，once，a far as，on condition that.
注意if与unless的区别：不能用and连接两个unless从句，即不能有…unless…，and unless….
但if…not and if…not却不受此限。
You won't lose your weight unless you eat less and unless you exercise more.（×）
但可以说…unless you eat less and exercise more.
注意状语从句中从句的省略现象
（1）连接词+过去分词
Don't speak until spoken to.
Pressure can be incrased when needed.
Unless repaired，the washing machine is no use.
（2）连词+现在分词
Look out while crossing the street.
（3）连词+形容词/其他
常见的有it necessary、if possible、when necessary、if any等。