题目

 —Where ____ Margaret have put the empty bottles?          —She ______ them away. They must be somewhere.          A．can; can’t have thrown     B．must; needn’t          C．must; must have thrown  D．can; must throw 答案：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。

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