Students should by all means______ their studies though there are a lot of entertainments inviting them.
| A．devote to | B．fix on | C．concentrate on | D．pay their attention |
We’d better hurry. Our teacher ________ us.
| A．wait for | B．must wait for | C．must be waiting for | D．has waited for |
The teacher as well as the students _______planting trees.
| A．are | B．is | C．has | D．have |
_______ is known to all, smoking is harm our health.
| A．As, for | B．As, to | C．It, for | D．It, to |
__surprised me most was ___ Mary spoke Chinese just like a native speaker.
| A．That, what | B．Which, that | C．What, that | D．That, that |
--- Would you mind my opening the window. It is too hot.
---- .
| A．No, please don’t | B．Yes, go ahead | C．Yes, please | D．No, go ahead |