We _____in this pool when we were young ,but now it ____fish .
| A．are used to swim ,used to keep |
| B．are used to swimming , is used to keep |
| C．used to swim，used to keep |
| D．used to swim，is used for keeping |
Every year lots of trees ____________ to make our country more beautiful.
| A．is planted | B．was planted | C．are planted | D．were planted |
A: Listen! Is it Linda singing in the next room?
B: No, it __________ be her. She is still in Shanghai.
| A．can’t | B．couldn’t | C．may not | D．might not |
A: ______________ beautiful city!
B: Yes. Lots of tourists come to visit it every year.
| A．How | B．What | C．How a | D．What a |
A: Alice, please tell Eric to call me when he _________ back.
B: No problem.
| A．come | B．comes | C．came | D．will come |
There are _____________ people in the supermarket. It's so crowded.
| A．hundred | B．hundreds | C．hundred of | D．hundreds of |