问题补充:
You are supposed the work yesterday but you forgot.
A. to finish
B. to be finishing
C. to have finished
D. had finished
答案:
A. to finish
B. to be finishing
(答案→)C. to have finished
D. had finished
解析:考查非谓语动词。be supposed to do应当做,根据语境昨天已经完成工作,故用不定式的完成时态,选C。