用 can may must have to及否定形式填空
用 can may must have to及否定形式填空
用should,shouldn’t,must,mustn’t,needn’t,can’t ,may,have to 填空
用ought to,can,may,must,need填空
用can,can't,must或have to 填空
用can,must,musn't,have to,has to填空
用should,may,can,must填空
用have to的适当形式或must填空
用情态动词can,may,must或他们的适当形式填空
将下列句子改成否定句和疑问句,用can,may,must,can't,mustn't,needn't填空
can may must should have to need 的区别
选用can(not),must(not),should(not),have to,may
情态动词can,may,must的肯定形式和否定形式是什么