couldbe,mightbe,mustbe,cannotbe表推测有什么区别

must be 、语气最强 表示 一定---- 选must be时，一般题目都会给予充分的信息。比如下面重庆的高考题： 1. —Hi, Tom. Any idea where Jane is? （答案 c ） —She _____in the classroom. I saw her there just now. A. shall be B. should have been C. must be D. might have been 2. I can’t leave. She told me that I_____ stay here until she comes back. （答案 b) A. can B. must C. will D. may could be 表示对过去的推测，翻译成可能----， In this case, however, the costs could be enormous.在这一情形中，花费可能是巨大的。 cann't be 表示不可能，是must be 的否定形式， However, there are areas of your life that can't be fulfilled by just work alone. 然而，生活中还有一些方面不是仅仅靠工作一方面就能完善的。 You can't be a positive person all of the time. How do you do it? 你不可能事事都顺心，你是怎样做到一直都这么积极乐观的呢？ might (be) 推测的可能性最小，翻译成也许---- Idon'tagree withhimonthatalthoughhemightberight . 在那一点上，我不同意他的意见，尽管他也许是对的。 —Where is my dictionary? I remember I put it here yesterday. （答案 D） —You it in the wrong place. (2007 江西卷) A. must put B. should have put C. might put D. might have put