I regret _____ hard at school, or I would have succeeded in passing the exam.
A. not to work B. having not worked
C. to have not worked D. not having worked
I regret _____ hard at school, or I would have succeeded in passing the exam.
A. not to work B. having not worked
C. to have not worked D. not having worked
D
regret doing sth.后悔做过某事；regret to do sth.遗憾（抱歉）地要做…