–I could not start my car this morning due to the cold weather.
--No wonder you were late. You have used mine. I was not using all the morning.
A. should
B. must
C. could
D. might
网友回答
A. should
B. must
(答案→)C. could
D. might
解析：考查情态动词。should 应该，must 必须，could 能，might 可能，句意：由于寒冷的天气今天早晨我不能把我的车启动起来。难怪你晚了，你本可以用我的车，整个上午我都没用。could have done 本可以做某事，而实际上没有做，所以选C。