(
课件网) Unit 3 The World of Science Grammar 1. Identify and summarize the forms and functions of present perfect passive through observation. 2. Apply it correctly in different contexts and situations. Learning objectives She has finished her homework. Someone has broken the window. Activity 1 Describe the pictures with Present perfect tense. 表示说话时已经完成的动作，而且这个动作的结果对现在仍有影响 He has taught in our school for 30 years. 表示动作发生在过去，但一直持续到现在，并且有可能继续持续下去 The enemy has killed you. You have been killed by the enemy. Activity 2 Compare the sentences and find out the difference 被动 1.I guess you have been asked about the title of your book before. 2. I guess someone has asked you about the title of your book before. 3.New inventions like 3D printers have been used to make replacement hearts and bone parts. 4. People have used new inventions like 3D printers to make replacement hearts and bone parts. 找出下面句子的谓语结构，哪些是主动？哪些是被动？ 被动 主动 主动 The New Age of Invention has just been published. 2. In addition, important advances have been made in medicine and environmental science thanks to increasing computer power. 3. I’ve also been told that you’re an inventor yourself. 4. Nothing like this has been invented yet and I’d say…… Look for more sentences with the present perfect passive. 现在完成时及其被动语态 构成： 现在完成时的主动语态：have/has (not)＋done 现在完成时的被动语态：have/has (not) ＋ been + done 现在完成时的一般疑问句形式：Has/Have＋主语＋been done 现在完成时的特殊疑问句形式： 特殊疑问词＋has/have＋主语＋been done Our classroom has been cleaned. You needn't clean it now. 我们的教室已经被打扫过，你现在没必要再打扫了。 These flowers have been watered. You can go home. 这些花已经被浇水了，你可以回家了。 英语中谓语动词的时态的含义 时,即每种时态所涉及的动作行为所对应一个时间段,学习时态一定要先弄明白每种时态所在语境中对应的时间. 这是句意理解的问题 态,即每种时态所涉及的动作行为进行到什么地步，而语态指的是主动还是被动。 使用谓语动词的各种时态时务必记得从这2方面做好分析，不要遗漏。 现在完成时是以过去为时间起点，该动作行为是过去时间发生的，但是说话人着眼于现在的结果，而不是过去。 从本质上来说，现在完成时是属于现在时间段的时态。 1. 基本用法: 1) 影响性用法:表示一个动作发生在过去, 已经完成, 且对现在造成影响或结果。 e.g. ①He has left the city.（结果:他不在这个城市） ②Someone has broken the window.（结果: 窗户仍破着） 2) 持续性用法:表示一个动作从过去持续到现在, 且可能继续持续下去或可能到此结束。 e.g. ① We have been busy this afternoon. ② His first novel has received good reviews since it came out last month. 他的第一本小说自从上个月出版以来就很受欢迎。 2. 用现在完成时的典型场合: 1) “since＋过去时间”或“since接从句（从句中用一般过去时）”则句中用现在完成时。 e.g. ①I haven’t seen her since last week. ②Where have you been since I last saw you 2) 句中有so far, to date, in （for/during）the past （last）years（months… ）, ... ...
