I admire my English teacher. I can remember very few occasions ________ she stopped working because of ill health.
| A．that | B．when | C．where | D．which |
People are advised not to smoke at home, since passive smoking is ________ to people around them. Which is Not proper for the blank?
| A．dangerous | B．protective | C．hazardous | D．Risky |
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 |