1、第 10天含有情态动词的被动语态重要程度： 难易程度：Teenagers should _ to choose their own clothes. A. be allowed B. allow C. allowed D. to allow【参考答案】A【拓展延伸】含有情态动词的被动语态1、构成含有情态动词的被动语态的结构为情态动词+助动词 be+及物动词的过去分词情态动词指 can, may, must, should等。The flowers should be watered.应该给花浇水了。Tables can be made of stone.桌子可由石头做成。Teenagers s
2、hould be allowed to go out with their friends.青少年应该被允许和朋友外出。2、句式（1）肯定形式：主语+情态动词+be+及物动词的过去分词+by 短语（by 短语可省略） 。（2）否定形式：主语+情态动词+not +be+及物动词的过去分词。（3）一般疑问句：情态动词+主语+be+及物动词的过去分词？（4）特殊疑问句：特殊疑问词+情态动词+主语+be+及物动词的过去分词？Waste paper should not be thrown here. 废纸不应该被扔在这里。Must the trees be watered now? 这些树必须现在浇水
3、吗？Should it be done by Li Ming? 这件事应该是李明干吗？三、含有情态动词的主动句与被动句之间的转换含有情态动词的主动句变为被动句时，要把主动句中的宾语变成被动句中的主语；主动句中的谓语变为情态动词+be+及物动词的过去分词；主动句中的主语变为介词 by的宾语（如果不强调动作的执行者，by 短语常可省略） 。1. 将下列句子改为被动语态We must speak to the old people politely.Must the old people _ _ _politely?Dad cleaned the car yesterday.The car _ _
4、by Dad yesterday.We often water these young trees.These young trees _ often _ by us.The boy broke the window yesterday.The window _ _ by the boy yesterday.I will give him a camera as a present.A camera _ _ _ to him by me as a present.2. More trees must _here.A. be planted B.planted C. to plant D. pl
5、ant1. 将下列句子改为被动语态was cleaned 【解析】考查一般过去时的被动语态。其基本结构为：主语+was /were+动词的过去分词。被动语态变为主动语态，要将被动语态的宾语变为主动语态的主语，将被动语态的主语变为主动语态的宾语，注意变换时时态要保持一致。主语是单数名词 The car，由 yesterday可知应用一般过去时，故填 was cleaned。will be given 【解析】由上句中的 will可知用一般将来时，本句考查一般将来时的被动语态，其基本结构为：主语+will +be+动词的过去分词。2. A 【解析】句意：在这儿更多的树需要被种。此题考查含有情态动词的被动语态，根据句意可知选 A。与 学 习 思 考_
