We——last night, but we went to the concert instead A must have studied B might study C should have studied D would study
—Hi, Ben! You look upset. _________ —I failed in the exam again.
—Did you know Bob before you came here?—In fact, never _________ him.
—If you can _________ this goal, you will be in a much better position. —We'll do our best.
I _________ to go to the concert with my cousin, but on second thoughts, I gave up the idea.
Only after we have taken into consideration all aspects of the problem _________ the right decision.