2015年職稱(chēng)英語(yǔ)衛(wèi)生類(lèi)語(yǔ)法否定句：
他的設(shè)計(jì)肯定還沒(méi)完成。
誤：He mustn't have completed his design.
正：He can't have completed his design.
對(duì)比較有把握的推測(cè)，肯定句中用must，而否定句中用can't，對(duì)過(guò)去的推測(cè)，在must和can't后接完成形式。
2015年職稱(chēng)外語(yǔ)等級(jí)考試報(bào)名指南
