Mike has recently caught A-H1N1. ________, he will have to be away from school for several days.
3. —How long are you staying there? — _____depends.
4. I hate _______ when young people speak to the elderly in a rude way.
5.Is ____ necessary to complete the design before National Day?
6.I don’t think ____ possible to master a foreign language without much memory work.
7.Does ______ matter if he can’t finish the job on time?