2016高考二輪復習英語學案專題七 情態(tài)動詞和虛擬語氣
3.注意分清適用句型
即要分清所考查的情態(tài)動詞是用于肯定句型，還是用于疑問句型或否定句型，同時還要注意情態(tài)動詞在某些特殊情況下所使用的特殊句型。
4.弄清說話者的語義、語氣推斷屬于哪個時間段的情況，正確把握隱含、混合等虛擬語氣。
5.掌握固定句式，從固定句式著手，套用虛擬語氣句型。
1.—catherine, i have cleaned the room for you.
—thanks. you _________it. i could manage it myself.
a. needn’t do b. needn’t have done
c. mustn’t do d. shouldn’t have done
【解析】b 句子的語境是：“我自己能做”，所以“你本不必做的”。選a還是b呢？根據(jù)前面一句中的 have cleaned 可知，動作已經(jīng)發(fā)生，所以此處談論的是一個過去情況，故選 needn’t have done。
2. this cake is very sweet. you _________ a lot of sugar in it.
a. should put b. could have put c. might put d. must have put
【解析】d前文說“蛋糕很甜”，下文的語境顯然應該是“你一定是在里面放了很多糖”，故用“must+完成式”表示對過去情況的肯定推測。
3. —the woman biologist stayed in africa studying wild animals for 13 years before she returned.
— oh, dear! she _________ a lot of difficulties!
a. may go through b. might go through
c. ought to have gone through d. must have gone through
【解析】d由上文的stayed可知，此題是對過去情況有把握的肯定推測。句意為“那個女生物學家呆在非洲研究野生動物XX年才回來。”“天啊！她一定經(jīng)歷了不少苦難！”
4. helen _________ go on the trip with us, but she isn’t quite sure yet.
a. shall b. must c. may d. can
【解析】c由于下文說“她還沒有把握”，所以前文要用may表示沒有把握的肯定推測，即“可能會與我們?nèi)ヂ眯小薄?br>5. —i’ve taken someone else’s green sweater by mistake.
—it _________ harry’s. he always wears green.
a. has to be b. will be c. mustn’t be d. could be
【解析】d 后文說“他總是穿綠色衣服”，據(jù)此語境可推知，這件衣“可能是”哈利的，could表示可能性。
6. —do you know where david is? i couldn’t find him anywhere.
—well. he _________have gone far—his coat’s still here.
a. shouldn’t b. mustn’t c. can’t d. wouldn’t