–Why, I couldn’t get you on the phone this morning.
--We tennis in the yard when you called.
A. must be playing
B. could be playing
C. must have played
D. must have been playing
网友回答
A. must be playing
B. could be playing
C. must have played
(答案→)D. must have been playing
解析:可联系答.案.网客服索取。