Question

1．Your room must have been cleaned yesterday，          ？（　　）

• A． wasn't it
• B． haven't it
• C． hasn't it
• D． mustn't it

Answer 1

分析 你的房間昨天肯定被打掃過(guò)，是嗎？

解答 答案A．反意疑問(wèn)句，注意前否定，后肯定；前肯定后否定，it替代your room，結(jié)合yesterday，當(dāng)must+have done表示對(duì)過(guò)去的情況進(jìn)行推測(cè)，問(wèn)句要根據(jù)陳述部分謂語(yǔ)的情況用"didn't+主語(yǔ)"或"wasn't/weren't+主語(yǔ)"；這里主語(yǔ)your room，是動(dòng)詞clean的承受者，結(jié)合yesterday故用過(guò)去時(shí)被動(dòng)語(yǔ)態(tài)was+cleaned，故答案是A．

點(diǎn)評(píng) 當(dāng)must+have done表示對(duì)過(guò)去的情況進(jìn)行推測(cè)（一般句中有明確的過(guò)去時(shí)間狀語(yǔ)），問(wèn)句要根據(jù)陳述部分謂語(yǔ)的情況用"didn't+主語(yǔ)"或"wasn't/weren't+主語(yǔ)"；如果強(qiáng)調(diào)動(dòng)作的完成（一般沒(méi)有明確的過(guò)去時(shí)間狀語(yǔ)），問(wèn)句要用"haven't/hasn't+主語(yǔ)"．She must have read the novel last week，didn't she？她上星期一定讀了這本小說(shuō)，是嗎？You must have told her about it，haven't you？你一定把這事告訴她了，是嗎？