—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?

—Have you invited Alice to our party?—Yes. But she _____ come; she is busy nowadays.

---_____book is this? --- I think it _____ Carla’s. It has his name on it.

—Are you coming to Jeff's party?—I'm not sure.I ________ go to the concert instead.

—Can I pay the bill by check?--- Sorry, sir. But it is the management rules of our hotel that payment ____ be made in cash.