人教必修1·第1单元·重难点详解(12)■本站特约作者 陈根花 供稿　　23. by doing sth是什么意思　　【教材原句】　　Your friend, who doesn’t work hard, asks you to help him / her cheat in the exam by looking at your paper. (p.1)　　译文：你一个平时学习不用功的朋友要你帮他（她）在考试中作弊，让他（她）看你的考试答卷。【用法说明】　　by doing sth 的意思“通过做某事”，其中的介词 by 表示方式。这类短语在句中主要用于状语（即方式状语）。如：　　A：How did you finish the job so soon? 你怎么这么快就干完了?　　B：By climbing on to the roof. 爬到屋顶上干的。　　They escaped by sliding down a rope. 他们是从一根绳子上滑下来逃走的。　　You can improve your English by reading more. 多看书可以提高你的英语水平。　　但有时也可用作表语。如：　　The virus’s usual transmission route is by sneezing. 这种病毒通常是通过打喷嚏传播的。　　The only way to tell if you like something is by trying it. 要确定是否喜欢某事物，唯一的办法是试一下。　　　　24. should have studied 是什么意思？　　【教材原句】　　You will tell him / her that he / she should have studied, so you don’t let him / her look at your paper. (p.1)译文：你会告诉他（她），他（她）本来应该动力学习的，所以你不让他（她）看你的答卷。【用法说明】　　should have studied 为“情态动词 should + 动词完成式”结构，其用法如下：　　1. 表示推测　　对可能已经发生的情况作猜测，其意为“大概已经”“应该已经”。如：　　The lettershould have arrived by now. 信现在该到了。　　The train should have already left. 火车大概已经开走了吧。　　I can’t think why he should have been so angry. 我想不通他怎么会这样生气。　　2. 表示本该发生而实际上未发生的情况　　即用于谈过去未发生，或可能发生也可能未发生的事情，通常译为“本来应该”“早就应该”。如：　　Ishould have stopped smoking. 我本该戒烟。　　You should have finished. 你早就应该完成了。　　You should have told us earlier. 你应当早点告诉我们的。　　You should have come with us. 你本该和我们一起来。　　This should have been planned well ahead. 这些应当提前计划。　　George never should have joined the army. 乔治本来就不该参军的。　　注意：若用于否定式，则表示发生了不该发生的事或指可能尚未发生的事。如：　　You shouldn’t have parked there. 你本不该把车停在这里。　　You shouldn’t have started smoking. 你本不该开始吸烟。　　They shouldn’t have been told about it. 这事是不应当告诉他们的。　　You shouldn’t have opened her letter. 你是不应该拆她的信的。　　Really, youshouldn’t have done it. 说真的，你本不该做那件事。　　3. 表示惊讶　　I’m sorry that this should have happened. 我很遗憾，竟发生了这事儿。　　It’s strange that he should have left without telling us. 奇怪，他竟没有和我们说一声就走了。　　I was surprised that he should have made the same mistake. 我奇怪他犯了同样的错误。　　　　 说明:引用此文请注明出处,并请保留该文章链接地址,谢谢~~