—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
网友回答
(答案→)A. can; can’t have thrown
B. must; needn’t
C. must; must have thrown
D. can; must throw
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。