2019-2020学年度人教版必修五Unit3Life in the futurePeriod4Grammar教案(6页word版)
2019-2020学年度人教版必修五Unit3Life in the futurePeriod4Grammar教案(6页word版)第3页

● Mosquitoes should be completely exterminated where found.

● Retirees in good health should be invited to return to work wherever needed.

(3)由 if, unless 引导,表示"条件",如:

● If kept for too long, some medicines will lose their effectiveness.

● We have made a point of not attacking unless attacked.

(4)由 though, although, even though 连词引导,表示"让步 ",如:

● Though warned of the danger, they still went mountaineering.

● Even though defeated for a second time, our team did not give up hope for the ultimate victory.

此外,过去分词短语还可以和介词"with"或"without"连用,具副词作用。如:

● With the water pipe choked, there wasn't any more water for use.

● Without anything left in the kitchen, the Wangs decided to eat out.

最后,过去分词短语,在适当情况下,可以有自己的主语而变成独立结构(the absolute construction),如:

 ● The old man listened, his head inclined to one side

4. Studying the past participle as the attribute

过去分词作定语,在语态上,表被动;在时间上,表示动作已经发生或完成,与它所修饰的名词有逻辑上的动宾关系。过去分词作定语时,所修饰的名词在逻辑上相当于被动句中的主语,过去分词相当于谓语。

  过去分词作定语表示动作在谓语动作之前发生,已经完成并具有被动意义。有时也不表示时间性。作定语的过去分词一般由及物动词变来,因为只有及物动词才有被动意义。例如: He is a teacher loved by his students. 他是个很受学生爱戴的老师。

  也有用不及物动词的过去分词作定语的情况,一般作前置定语,它不表示被动意义,只表示主动意义,强调动作完成。不能像及物动词的过去分词那样放在名词后面作定语。例如: fallen leaves 落叶, retired workers 退休工人, the risen sun 升起的太阳

  注意下面过去分词作定语的几种情况:

A. 单个的过去分词作定语一般放在被修饰的名词之前。例如: