Question

【题目】—Why! I couldn’t get you on the phone this morning.

—We ________ tennis in the yard when you phoned me.

A. could be playing

B. must be playing

C. must have been playing

D. should have played

Answer 1

【答案】C

【解析】考查情态动词和时态。句意：——为什么今天早上打电话找不到你？——你给我打电话的时候我们一定是在院子里打网球。must have done表示肯定做了某事；must have been doing表示当时肯定在做某事。答句强调你打电话的这个时间点我们正在做某事，所以要用must have been doing形式。故选C。