Mr.Smith warned his daughter ______ after drinking.
| A．to never drive | B．never driving | C．never to drive | D．never drive |
He stumbled(绊倒)on the _______ ground and fell flat on his face.
| A．undeniable | B．unfair | C．unavoidable | D．uneven |
Many students today suffer from ________ problems, since they are under too much pressure.
| A．recreation-related | B．pollution-related |
| C．stress-related | D．pollution-free |
________ energy is generated from natural resources—such as sunlight, wind, rain, tides and so on.
| A．Recyclable | B．Non-renewable |
| C．Rechargeable | D．Renewable |
Effective measures have been taken to prevent _______pollution.
| A．exhausted gas | B．exhausting gas |
| C．exhaust gas | D．exhaustion gas |
It worried her a bit ____ her hair was turning grey.
| A．while | B．that | C．if | D．for |