--Listen! Tom is singing in the next room.--It _______ be Tom. He has gone to Shanghai. 

--- Amazing ! You _________ wear slippers at work. --- Don’t you know it’s a fashion ?

 --- Is John coming by train?--- He should, but he _______ not. He likes driving his car.

-- Mum，can I go on a holiday with my classmates this summer vacation?-- OK．You __________ have a chance if you get along well with your studies．

Overloaded with work, school teachers now get far less sleep than they ______.