—How unhappy your roommate looks!—Yes, but he's not willing to tell me what it is ________ is troubling him.
I will have to find some other work, for I can't __________ this loud noise any more.
I can __________ the house being untidy, but I hate it if it's not clean.
He decided that he would drive all the way home instead of __________ at a hotel for the night.
— Happy birthday! —Thank you! It's the best present I __________ for.
Most American children go to state schools, but the private schools __________ be very good.