—Where Mary have put the empty bottles? — She them away. They must be somewhere. A. can;

问题补充：

—Where Mary 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; mustn’t have thrown

答案：

(答案→)A. can; can’t have thrown

B. must; needn’t

C. must; must have thrown

D. can; mustn’t have thrown

解析：考查情态动词ｃａｎ的用法：ｃａｎ＋完成时，表示推测的时候，ｃａｎ用于疑问和否定句，第一空是用于疑问句，用ｃａｎ，第二空是用于否定句，ｃａｎ＇ｔｈａｖｅｄｏｎｅ过去不可能做了什么，句意：玛丽把空瓶子放在哪里呢？――她不可能扔了的。一定在什么地方。选Ａ。