单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,.,*,1.While walking the dog,you were careless and it got loose and was hit by a car.,While you were walking the dog,you were careless and it got loose and was hit by a car.,2.,While crossing the road,you should be careful.,While you are crossing the road,you should be careful.,.,在时间、条件和让步等状语从句中,如果从句主语和主句的主语一致,且从句的谓语含有be动词的某种形式,从句的主语和be动词可以省略,并且要同时省略。,状语从句的省略,.,状语从句省略句的结构：,连词+分词（-ing、-ed)/形容词,特点：,1.从句主语与主句主语相同,2.从句中谓语动词含有be动词,.,一般说来省略现象多出现在下列五种状语从句中：,1.由when,while,as,before,after,till,until,once等引导的时间状语从句；,2.由whether,if,unless 等引导的条件状语从句；,3.由 though,although,even if,whatever等引导的让步状语从句；,4.由 as,than 等引导的比较状语从句；,5.由as,as if,as though 等引导的方式状语从句.,.,熟读深思,阅读下列句子,指出划线句中省略的单词,1.,The country singers were playing the guitar,while singing.,(while,后省略了,_),they were,.,2.,When asked,to answer questions,you should stand up.,(When 后省略了_),3.He will help us do it,if necessary,.,(if 后省略了 _),you are,it is,当从句的主语是 it,谓语动词中又含有系动词be 时,可以把it和系动词be一起省略.,if necessary/possible/if true/so/not,.,灵活运用,When 1_(travel)in Shanghai,I happened to meet my friend.We chatted for a little while.Even though,2 _(invite),I didnt have a drink with him because I was in such a hurry.,invited,traveling,.,