It will be a long time ______- he returns.
| A．until | B．before | C．when | D．after |
I smell something ____ ______ in the kitchen. Can I call you back in a minute?
| A．burning | B．burnt | C．being burnt | D．to be burnt |
.At the beginning of class, the noise of desks ____ could be heard outside the classroom.
| A．opened and closed | B．to be opened and closed |
| C．being opened and closed | D．to open and close |
_____and I’ll get the work finished.
| A．Have one more hour | B．One more hour |
| C．Given one more hour | D．If I have one more hour |
.This washing machine is environmentally friendly because it uses _____water and electricity than _____models.
| A．less; older | B．less; elder | C．fewer; older | D．fewer; elder |
---Mom, what did your doctor say?
---He advised me to live _____the air is fresher.
| A．in where | B．in which | C．the place where | D．where |