We asked the teacher to explain the difficult sentences again.-The teacher was asked to explain the difficult sentences again.

　　I found a poor girl lying on the ground.-The poor girl was found lying on the ground

　　My mother bought me a pair of new shoes.-I was bought a pair of new shoes; -A pair of new shoes was bought for me.

　　When we came to the theatre， we found all the seats occupied.-When we came to the theatre， all the seats were found occupied.

　　They paint their houses white in spring.-Their houses are painted white in spring.

　　The people in the town recognize him as a genius.-He is recognized as a genius by the people in the town.

　　有些动词，如let， make， hear， see， watch， notice， have(让，使)， feel 等，在主动语态中，其后面的不定式作宾语补足语时to 被省略，但在被动语态中需将to表达出来。在被动语态中，如果一个简单句中有两个动词，后一动词一定要加to.

　　I saw him turn round the corner.-He was seen to turn round the corner.

　　The teacher made the students copy the sentences many times until they could make sentences themselves.-The students were made to copy the sentences many times until they could make sentences themselves.

　　含有被动意义的主动语态：

　　(1)某些连系动词，如smell， taste， sound， prove， feel.

　　The flowers smell sweet.

　　The food tastes nice.

　　(2) 某些与can't， won't 等连用的不及物动词， 如move， lock， shut， open.

　　It can't move.(不能说 It can't be moved.)

　　The door won't shut.

　　The cloth washes well.

　　The poem reads smoothly.

　　The meat is cooking.

　　动词的语态部分主要应掌握被动语态的基本用法及其在不同的时态中的表现形式。

　　1.It remains a question when the new classroom building _________.

　　A. will be completed B. had been completed

　　C. would be completed D. has been completed

　　(答案 A)

　　2.My mother knows Jane; they _____ to each other at a party.

　　A. have been introduced B. are introduced

　　C. were introduced D. had been introduced

　　(主动语态：introduce sb. to sb.)

　　(答案 C)

　　被动语态部分还须特别注意动词make， hear， see等词，其后面用动词不定式作补足语时，to 应该保留。

　　Those who won't work should be made to work.