–Sorry, Professor Smith. I didn’t finish the assignment yesterday. --Oh, you _____ have done it as yesterday was the deadline. A. must B, mustn’t C, should D. shouldn’t
Tom tried to __________ in German.
I wonder how many years ago ___________.
He said that he would write to us but so far we ___________ from him.
__________ good exercise.
I don’t know who invented __________ telescope, but I think it is __________ most useful invention.