We （ ） last night, but we went to the concert instead.
（A）must have studied
（B）might study
（C）should have studied
（D）would study
I （ ） asleep in the corner, for I remember nothing of what happened during the night.
（A）might fall
（B）must fall
（C）must have fallen
（D）can have fallen
My wallet is nowhere to be found. I （ ） when I was on the bus.
（A）must have dropped it
（B）must drop it
（C）should have dropped it
（D）ought to have dropped it
