(
课件网) THE PERFECT Indentify the tense of the sentences and write the number in the correct columns. Present perfect Present perfect continuous Past perfect Past perfect continous 1 Natural cloning has been going on for generations. 2 Gardeners have been using a form of cloning when they take a cutting from a plant … 3 For years, there had been attempts to clone animals. 4 Cloning primates has been proved to be “much harder” than cloning other species. 5 Dr. Sun Qiang said they had been wholly devoted to the research … 6 Dr. Sun Qiang said they had been taking care of more than 1,000 monkeys 24 hours a day, 7 days a week … Present perfect continuous Present perfect continuous Past perfect Past perfect Present perfect Past perfect continous Present perfect Present perfect continuous Past perfect Past perfect continous 4 1 2 3 5 6 完成时 完成时表示一个完成的动作。用来表示现在、过去或者未来某个时间点已经或将会完成的动作。完成时的构成一般是动词have + verb-ed形式。 现在完成时的用法 1. 表示过去发生的事情对现在产生的影响。常用的状语有: already, ever, just(刚刚), yet, before等。 e.g. He has switched off the light. The concert has already started. 2. 表示一个动作开始于过去, 持续到现在, 也许还会持续下去。常与之连用的时间状语有: lately, recently, in the last (past) few days / years, since, then, up to now, so far等。 e.g. In the past few years, great changes have taken place in my hometown. He has written 8 books so far. 3. 在“最高级+名词”或 “It/This is + the + 序数词 + time”之后的从句中，谓语动词常用现在完成时。 e.g. This is the first time (that) I have come here. 4. have gone to意为 “去某地了”, 表示此人现在还没回来。 e.g. He has gone to the zoo. He has gone to live abroad. 5. have been to意为 “去过某地”, 表示此人已经回来了。 e.g. Have you ever been to Shanghai He has been to see his teacher. 6. 瞬间动词可以用于完成时态，但不可以接表示一段时间的状语。 e.g. ( √ ) He has finished the work. (×) He has finished the work for an hour. 1. 一件事情发生在过去，而另外一件事先于它发生(即表 “过去的过去”)，那么发生在前的动作要用过去完成时。 e.g. She had learned some English before she came to the institute. He said that he had been abroad for 3 years. 过去完成时的用法 2. 表示从过去某一时间开始, 一直延续到过去的另一时间的动作, 常用的时间状语有: by / until / before / by the end of + 过去的某时间。 e.g. By then he had learned English for 3 years. Until then he had known nothing about it yet. 3. hope, expect, mean, intend, want的过去完成时表示过去未曾实现的愿望或意图。 e.g. I had hoped to see more of Shanghai. 4. 在“hardly / scarcely / barely … when …”和 “no sooner … than …”句型中，when和than从句里用一般过去时，主句用过去完成时，且用倒装，表示 “刚……就……”。 e.g. Hardly / No sooner had I got home when / than the rain poured down. 5. 在“It was / had been + 一段时间 + since从句”中, since从句的谓语动词用过去完成时。 e.g. It was ten years since we had had such a wonderful time. 6. 在 “Tha ... ...
