We have friends to help us fight against pollution, and trees are one of ________.
| A．themselves | B．they |
| C．their | D．them |
We should take ____ active part in the battle to stop the germs.
A.theB.anC. /
_______ necessary for us _______ English well.
A.It’s; to learnB.It’s; learn C.That’s; learn
—Watching TV too much _______ bad for your eyes.
—I’ll go to bed right away.
A.beB.are C.is
We must keep our classroom______.
A. cleaning B. cleanC. to clean
—Would you mind _______ us in the game?
—Not at all.
A.joiningB.join in C.joining in