The professor at 8 o’clock but he has not shown up yet which worries all of us.A. was supp

问题补充：

The professor at 8 o’clock，but he has not shown up yet，which worries all of us.

A. was supposed to arrive

B. must have arrived

C. might have arrived

D. was supposed arriving

答案：

(答案→)A. was supposed to arrive

B. must have arrived

C. might have arrived

D. was supposed arriving

解析：

试题分析:考查虚拟语气。A应该到达；B肯定已经到了；C可能已经到了。根据后面句子的时态判断此处是对现在情况的推测，而B、C选项均为对过去发生事情的推测，所以排除B、C选项； D选项形式错误，故A为正确选项，句意：教授本应该8点钟到，但是他现在还没露面，这让我们非常担心。