Unit 10 You're supposed to shake hands.Grammar Focus 4c— 单元同步语法精讲精练be supposed to的用法 1．be supposed to 意为“应该做某事、被期望做某事”。用来表示根据规定，人们不得不做的事，或期待将要发生的事，与 should/ought to 相似，后接动词原形。 2．be supposed to的疑问句是将 be的相应形式提到主语前。如： When are they supposed to arrive？他们应该什么时候到？ 3．be supposed to do 的否定句是在 be 动词后面加 not。如： You aren't supposed to smoke.你不应该抽烟。 【拓展】(1)be supposed to do sth.相当于 should/be expected to do sth.。如： You are supposed to answer the teacher‘s question. ＝ You are expected to answer the teacher’s question. 你应该回答老师的问题。(2)suppose 的用法。当 suppose 意为“猜想，觉得，假定”时，后常接 that 引导的宾语从句。对 that 宾语从句进行否定时，否定前置，变成 I don't suppose that... 。类似用法的动词还有 think ， guess ， believe等。如：I suppose that my father will be back in half an hour. 我觉得我父亲会在半小时后回来。I don't suppose she will agree. 我认为她不会同意。It＋be＋adj.＋to do sth.的用法 此结构中 it 为形式主语，真正的主语是形容词之后的动词不定式。意为“做某事怎么样”，相当于 doing sth.is adj.。如： It's important to be on time.＝Being on time is important.准时很重要。 一、单项选择。1.To keep safe ， everyone ________ to wear a seat belt in the car.A ． is supposed B ． supposedC ． are supposed D ． will suppose2 ．— Henry ， you ________ tell the teacher if you want to go out of the classroom.—Sorry ， sir.A ． are supposed to B ． are surprised toC ． are afraid to D ． are mad to3 ．— It's ________ your chopsticks into my food.—I'm sorry.I won't do that again.A ． polite to put B ． impolite to putC ． kind of putting D ． generous putting4 ． It's not worth ________ time on it.A ． paying B ．...
