—Whose schoolbag is this?—It ___________ be Mary’s. It has her name on it.

—I wonder why Suzan looks worried today.—I’m not sure, but she ________a small accident driving here.

You _____ all those clothes! We have a washing machine to do that sort of thing.                                                      

There ______ little water in the river.

________ people used the computer thirty years ago, but now it’s very popular.