Unit 3 The world of Science Using language（Present perfect passive）课件-2021-2022学年高中英语外研版（2019）必修第三册

Unit 3 The world of Science Using language： Present perfect passive 1.He cleans the room every Sunday. 2.What did you use it for ? 3.He can make some machines. 4. He has already read this book. 把下列句子改写为被动语态： The room is cleaned every Sunday. What was it used for? Some machines can be made. This book has already been read. 被动语态的使用情况： 1. 不知道或者没有必要说明动作的执行者是谁； 2. 强调动作的承受者，而不是动作的执行者； 3. 动作的执行者很模糊; 4. 有时候为了礼貌的需要，避免说出动作的执行者。 例如： 1.Such books have been written for children. 2.All the products have been tested. 3.The letter has been opened. 4.They have been told many times not to make noises. c I guess someone has asked you about the title of your book before. d People have used new inventions like 3D printers to make replacement hearts and bone parts. a. I guess you have been asked about the title of your book before. b. New inventions like 3D printers have been used to make replacement hearts and bone parts. Compare them with the following sentences and answer the ques