—The research on the new flu virus vaccine is challenging and demanding. Who do you think can do the job?     —______ my students have a try?

Tom likes driving and he ______drive his car to the party, but I’m not quite sure about it yet.

— Mum, can I watch TV now? — No, you             . It's too late.

—Everyone in my class passed the exam.—Oh, really? It ________ difficult.

 ---_______I come back before five o’clock? ---No, you ________. But you________ be back later than seven o’clock