The room is in a terrible mess; it ________have been cleaned.
The chairman asked me to ________the report, because he didn't want to speak for too long at this meeting.
___ she couldn’t understand was ___fewer and fewer students showed interest in her lessons.
—-I can't stand you! I'm leaving.—________. See if I care.
--- Shall I get one more cake fro you, David?--- Thanks, but you ______. I’ve had enough.
Thank you very much. Without your help we ______ car started.