1.I need one more stamp before my collection______.　 (NMET)

　　 A.has completed　　pletes　　 C.has been completed　　 D.is completed

析：complete是及物动词，“邮集”是被人完成的，须从表被动意的C、D中选择。又因before等引导的时间状语从句中谓语要用一般现在时表将来，所以此题答案为D。

4.She took part in the sports meet.不能变为The sports meet was taken part in by her.因为象take part in,belong to ,own,have,hate,fail,contain等表状态动词没有被动语态。

被动语态考点分析

3.He lost heart.不可变为Heart was lost by him.因为象lose heart,make a face,keep silence,lose in thought这类动宾结构的固定短语只能用于主动式，不能用被动式。

2.We help each other/one another.不可变为Each other/One another is helped by us.因为相互代词不可作主语。

1.I teach myself French.不可变为Myself is taught French.因为反身代词不可作主语。

3.不定式在某些形容词之后，且与主语有动宾关系。常见形容词有：hard,defficult,easy,heavy,fit,good,comfortable,convenient,impossible等。例如：The problem is easy to do./The question is difficult to answer./The box is heavy to carry./The project is impossible to complete in a year.比较：The problem is to be done./The question is to be answered.没有形容词时，虽然不定式与主语是动宾关系，但必须用被动式。

2.一些连系动词的主动式+形容词。常见动look,smell,taste,sound,feel,prove,turn out等。例如：The apples taste good./The flower smells wonderful./The news proved/turned out true./Cotton feels soft.注：prove也可用于被动式，如：His answer(was) proved right.

1.不及物动词与状语连用，用以表示主语的品质和状态。常见动词是：cut,sell,read,write,fill,cook,lock,wash,drive,keep等。例如：This knife cuts well.这把刀好切。These books sell well.这些书好卖。The pen writes smoothly.这支笔写起来流畅。Meat won´t keep long in such hot weather.肉在这样热的天气里放不长久。The cloth washes well.这种布好洗。

5.双重被动式：主语+被动式谓语+不定式的被动式+其它成分

例如；These magazines are not allowed to be taken out of the reading-room./The murderer was ordered to be shot.

4.情态动词+be+过去分词

例如：This problem must be worked out in half an hour.