新概念二Lesson21（共42张PPT）.ppt

If I go to see my uncle ,I can read his books .It’s in two twos. A一分为二 B一文不名 C三心二意 D一举两得 D The words he gives on the computer is above my head . A 一目了然 B 终于醒悟 C 无法理解 D 头脑发昏 C 四、主动语态变为被动语态的步骤: They speak English. 主语 谓语 宾语 English is spoken by them. 主语 谓语动词的过去分词 宾语 (1)主动语态的宾语变成被动语态的主语。 (2)主动语态的谓语动词变为被动语态的谓语动词，即”“be+及物动词的过去分词”(be有时态、人称和数的变化)。 (3)主动语态的主语变为by的宾语。 五、被动语态的时态表示 被动语态的时态一般只通过be表现, 过去分词 不变。例如： 一般现在时: The trees are planted by the farmers. 一般过去时: The trees were planted by the farmers. 现在进行时: The trees are being planted by the farmers. 一般将来时：The trees will be planted by the farmers. 现在完成时：The trees have been planted by the farmers. 含情态动词的被动语态：The trees can (must,should) be planted by the farmers. 六、被动语态的几种句型： 肯定句 主语+be+过去分词+(by…) A sweet song was sung by her on the stage. 否定句 主语+be+not+过去分词+(by…) A sweet song wasn’t sung by her on the stage. 一般疑问句 Be+主语+过去分词+(by…) Was a sweet song sung by her on the stage? 特殊疑问句 疑问词+be+主语+过去分词+(by…) Where was a sweet song sung by her? 1. The woman asked the policeman for help. 2. The old man on TV tells a story on Sunday. 3. Do they use the box as a table? 4. She sent me a collection last week. 5. The teacher doesn’t teach us math this term. 新概念周五晚6.19作业 1.预习L22，写Summary. 2.家长签名 Exercise Structure 3. Passing planes can be heard night and day. You ____ them all the time. A. can heard B. can to hear C. can hear D. can be heard 4. It couldn’t be used then. It wasn’t _____ to use it. A. able B. allowed C. impossible D. possible 5. Over a hundred people must have been driven away. ________ they were. A.I think B. I’m sure C. Certain D. Of course 6. I am one of the few people left. So there _______ . A. are none left B. is one left C. are some left D. are a lot left 7.