—Where____Margarethaveputtheemptybottles?—She______themaway.Theymustbe

—Where ____ Margaret have put the empty bottles?—She ______ them away. They must be somewhereA.can; can’t have thrownB.must; needn’tC.must; must have thrownD.can; must throw

A解析本题考查情态动词+have done表示对过去事实的推测的用法。must have done用于肯定句中，疑问句否定句中应用can could代替must。故选A。

这个问题的回答的对