——Hi, Mike．Any idea where Mary is?
——She ____ in the classroom．I saw her there just now．

The World Wide Web is sometimes jokingly called the World Wide Wait because it ______ be very slow.

As is natural, a man as old as he ____ be very forgetful.

---  They live on a busy road．   
---  There ______ be a lot of noise from the traffic．

Visitors ________ take an animal or any other item prohibited by the Expo Bureau to the Expo Park.

．—______ I lock the lab before I go home?
—Don’t bother．I’ll check it myself later．

—Waiter! How soon can I get my food? I just have half an hour left before my train leaves.
—It ___________be ready in five minutes.

—I missed the first part of the film. It was really a pity.
—You __________ home half an hour earlier.

—Who______ it be that is knocking at the door?  
—It ______ be Father, but I’m not sure.

．—Where did you go last weekend?
—ChenDu, we got to the station almost half an hour earlier than the bus.
—So you _______ in such hurry.