We all should make a contribution to ______ our environment.
| A．protects | B．to protect |
| C．protecting | D．protect |
Don’t be afraid of asking for information ______it is needed.
| A．when | B．after | C．although | D．unless |
There great changes in our city in the past 10 years.
| A．were | B．had | C．have been | D．have had |
Hurry up!The play for ten minutes.
| A．has begun | B．began | C．has been on | D．has been |
Look! The tree is growing well. When______?
| A．was it planted | B．did it plant |
| C．will it be planted | D．is it planted[ |
—How often does the boy go to see his granny?
—.
| A．Twice a month | B．Two times a month |
| C．Three time a month | D．One time a week |