Last night Li Ping watched the football match at home when he his homework.
A. need have done
B. must haven done
C. should have done
D. could have worked
网友回答
A. need have done
B. must haven done
(答案→)C. should have done
D. could have worked
解析：考察虚拟语气。句意：当他应该写作业的时候，昨晚丽萍在家看足球比赛了。“should+have+done”意思是“本来应该做某事，而实际没做。”故选C。