It was a hard time for him. He tried his best to keep his head in a calm_______.
| A．environment | B．situation |
| C．practice | D．experience |
—What are _______ teachers doing?
—They are having a meeting.
A. this B. that C. those
There are a lot _____ students on the playground.
A. of B. in C. by
My mother asked me _____ the room.
A. clean B. cleans C. to clean
Tony has many Chinese ______.
A. stamp B. stamps C. a stamp
—May I come in?
—________
A. Come in, please. B. It doesn’t matter. C. That’s OK.