—How unhappy your roommate looks!—Yes, but he's not willing to tell me what it is _______ is troubling him.
– You left your umbrella. – ______. I’m becoming so forgetful these days.
I wonder whether you could ______ me ______ for the night when I come to London because all the hotels are full.
Mr. Li is remembered for his novels, but his scientific work is ______ equal importance.
– You might as well apply for that job — you’ve got nothing to ______ – OK, I will have a try.
James left his hometown when he was 16, and he ______ back there since.