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课件网) 第三课时 Section A（GF~4c） Revision Retell the passage about sharks in 3a What's the sharks' problem Why are they endangered Some facts and numbers about sharks at present How to save the sharks Reason: Comment: Shark fin soup: What people do: Result: Sharks’ situation: Environmental protection groups (Wild Aid & WWF): scientific studies: at the top of food chain, ecosystem, numbers drop, bring danger to... popular, southern China catch, cut off, throw… back into ... without, can no longer swim, slowly dies not only cruel , but also harmful to be endangered, although… ② numbers, have fallen, 90%, in the last 20 to 30 years. ② teach … about … ① ask...to...laws to stop… ①70 million,are caught, traded, industry No…, show…, be good for... We’re trying to save the earth. The river used to be so clean. The air is badly polluted. No scientific studies have shown that shark fins are good for health. We should help save the sharks. present progressive used to passive voice present perfect modal verbs Grammar Focus 现在进行时 现在进行时 基本 结构 基本 用法 标志词 be (am/is/are) + 动词-ing 1.表示现在正在进行或发生的动作。 2.表示现阶段或当前一段时间之内 正在进行的动作。 now、look、listen、these days等 Grammar 现在完成时 现在完成时 基本 结构 基本 用法 标志词 have/has + 过去分词 1. 表示过去发生或已经完成的动作对现在造成的影响或结果。 2. 从过去某一时间开始并一直持续到现在且还有可能持续下去的动作。 already、yet、ever、never、for +时间段、since +时间点、so far、in the last/past...years等 被动语态 主动语态表示主语是动作的执行者。被动语态表示主语是动作的承受者，即行为动作的对象。 I cleaned my room. → My room was cleaned by me. I saw him cross the road and enter the shop. → He was seen to cross the road and enter the shop. 在含有使役动词 (如：make) 或感官动词 (see、watch、notice、hear等) 的主动语态的句子中，这些词后常跟省略to的动词不定式，但是改为被动语态时则要把省去的to还原。 被动语态的构成 被动语态的基本结构：助动词be + 及物动词的过去分词 一般现在时的被动语态：am/is/are + 过去分词 一般过去时的被动语态：was/were + 过去分词 一般将来时的被动语态：will be/is going to be + 过去分词 含情态动词的被动语态：情态动词 + be + 过去分词 1. 情态动词一般没有人称和数的变化。 2. 情态动词后接动词原形。 3. 常用的情态动词有：can/could、may/might、must/have to、should/ought to、would、need等。 情态动词 used to used to意为“过去常常做某事”，后接动词原形。 used to句型的否定句形式：didn’t use to... used to句型的一般疑问句形式：Did + 主语 + use to... used to do表示过去常常做某事，而现在往往不做了； be used to doing表示习惯于做某事。 Practice Fill in the blanks with the correct forms of the verbs in brackets. Joe: _____ you ever _____ (take) part in an environmental project Ken: Yes, I have. I _____ (help) with a Clean-Up Day last year. It was _____ (consider) the biggest clean-up project this city_____ ever _____ (have). Joe: How many people _____ (take) part Have taken helped considered had had took 4a Ken: ... ...
