My sister often helps me ________ Japanese.
| A．studies | B．studying | C．studied | D．study |
— Must I take the medicine every day? — No, you ____.
A. must notB. may notC. don’t have to
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