A. may have been B. can have been C

A. may have been B. can have been C. must be D. can be55.You ________him, why didn’t you?A. ought to thank B. ought have thanked C. ought to have thanked D. ought thank 56.I ________have arrived a little earlier, but my car broke down.A. should B. could C. can D. can’t57.— ________we go out for a walk?— Great. Let’s goA. Shall B. Will C. May D. Should58.Though she was seriously ill, she ________ complete the work in time.A. would B. was able to C. was possible to D. might59.— Would you like to play chess with me?— Yes, ________.A. I’d B. I would C. I’d like D. I’d like to60.Tom is late. He ________the wrong bus.A. must take B. must have taken C. might take D. could take