省略句也是英语四级重要语法知识点的一部分，为了帮助考生能够在考试中取得高分，编辑老师整理了这篇14年12月英语四级语法考点：省略，希望可以帮助到大家!
在以as, than, when, if, unless等引导的从句中的省略: 在有些状语从句中,如果谓语包含有动词be,主语又和主句的主语一致a),或者主语是it b),就常常可以把从句中的主语和谓语的一部分(特别是动词be)省略掉.
Look out for cars when crossing the street.
When taken according to the directions, the drug has no side effects.
While there he joined in voluntary labour on a project.
Although not yet six months old, she was able to walk without support.
If not well managed, irrigation can be harmful.
Though reduced in numbers, they gained in fighting capacity.
This viewpoint, however understandable, is wrong.
Enemies, once discovered, were tightly encircled and completely wiped out.
She hurriedly left the room as though/if angry.
She worked extremely hard though still rather poor in health.
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