| Scientists will have to _____ new ways to solve the water problem. |
A. catch up with B. keep up with C. come up with D. make up with |
| The doctor _____ the man and found nothing serious with him. |
A. looked after B. looked for C. looked at D. looked over |
| The students of Class l got together to _____ the classroom. |
A. clean B. clean up C. cleaning D. cleaned |
| I would rather _____ than _____. |
A. go out; stay at home B. going out; stay at home C. to go out; to stay at home D. to go out; staying at home |
| —How many lessons do you usually have a day? —Six lessons a day, and each of them _____ 45 minutes. |
A. last B. lasts C. have |