He was busy writing a story，only _________ once in a while to smoke a cigarette．
| A．to stop | B．stopping |
| C．to have stopped | D．having stopped |
The ____________ of news that a flood is coming is a staff working in the weather bureau.
| A．resource | B．origin |
| C．root | D．source |
If you __________ drive so fast, you’ll run the risk of losing your license for six months.
| A．would | B．must |
| C．should | D．may |
--- Why didn’t you pay the accommodation rent?
--- The rent? ____________
| A．It all depends. | B．It’s up to you. |
| C．You are crazy! | D．That isn’t due yet. |
If it _________ not for all the cars and passers-by with cameras, you _________ think you have magically traveled back to the 14 century.
| A．is …will | B．had been… would |
| C．were… will | D．were…might |
Officials from China and France formally promised on Thursday to build a new type of economic partnership, while ________ business cooperation.
A. strengthened B. to strengthen
C. strengthening D strengthen