couldn't be bettle与could be worse 如何区分使用?

couldn't be bettle与could be worse 如何区分使用? You couldn't be more it couldn't be used then couldn't be prouder怎么翻译 lt couldn't be any worse I couldn't be more sure. You couldn't be more relaxed是什么意思? They( )be polite to their parents.A should B may C maybe D couldn’t I heard they went skiing in the mountains last winter.A.may not be B.won't be C.couldn't be D.mustn't be couldn't与can't的区别! can't与couldn't的区别 We tried to be friendly at first ,but it___ A can't work B couldn't work C won't work Dcan't work They( )be polite to their parents.A should B may C maybe D couldn’t选什么? 1) ---when wil your work be finished?--- sorry,I couldn’t ______ A.tell B say C speak d talk I couldn't stand ___ waiting for an hour.A.to keepB.to be kept C.keeping D.being kept ...I heard they went skiing last winter ....It ------have been true because there was littlesnow there .A may be B won,t be C couldn,t 汉译英：它们肯定不他的A,they mustn't be hers.B,they can't be hers.C,they needn't be hers.D,they couldn't be hers. A computer _____ think itself,it must be told what to do.A doesn't B may not C couldn't Dcan't说明下原因