It’s very dangerous ______ _ children to cross the busy street.
| A．for | B．of | C．to | D．by |
-- Did you read a book about customs last week?
-- Yes, I found ______ very useful to know the customs of foreign countries.
| A．that | B．this | C．it’s | D．it |
--You used to be quiet, ____you？
--Yes, and I used to be very shy.
| A．wasn’t | B．didn’t | C．aren’t | D．haven’t |
-- How do you study a test?
-- I studylistening to tapes.
| A．to; by | B．by; with | C．for; by | D．with; for |
--What’s the matter?
--They said I shouldn’t be allowedhere. They don’t allowin the waiting room.
| A．smoking; to smoke | B．to smoke; smoke |
| C．to smoke; smoking | D．smoking; smoking |
--Listen! Tom is singing in the next room.
--It _______ be Tom. He has gone to Shanghai.
| A．may | B．must | C．mustn’t | D．can’t |