—Listen! Is that Millie singing?—No. It _____ be Millie. She has gone to Beijing.

--- It’s so late. Our son______ be back!--- Don’t worry. I dare say he ______ have some extra work to do.

—May I smoke here，please?—I am afraid you           ．This is a non-smoking area．

Tina gets up late, so she _____ go to school by taxi.

---- I have taken someone else’s T-shirt by mistake. Is it Jane’s? ---- It _______ be hers. She seldom wears red.