Mr. Sun has devoted most of his time _______ his teaching work.
---When did you go to bed last night? ---______________
It rained so_______ that people could _______ go out yesterday morning.
—I find the more we study, the more difficulty we have _______ out Maths problems. —Oh, I agree with you. Maths is more and more difficult.
_____ Jack ______ Jim has been to China, but _____ of them knows much about China in fact.
— Have you found your lost mobile phone? —No, I haven’t found ___________, but I bought ___________ this morning.