--- Is this your ball, Nick?--- Yes,       .

-- _________ will the foreign students be back from Nanjing?--In two days, I think.

— I have heard you are going to change your job. Are you serious?—_______. I will quit my job.

You must have read about Mark Twain long ago, ____?

—_____ will you come back, Mum?—In ten minutes.