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

— Is there an express to Beijing tonight? — There ______ be, but you’d better call the booking office to make sure. 

We ______ the difficulty together, but why didn't you tell me?

(2013·银川高三一模)—Where is the post office?—It's just over there, at the end of the street. You ________    not miss it.

—________ we finish the work before class, Jack?—No, we_________ . We can do it after class.