As is well known, the brain performs a very important _______, which controls the nerve system of the body.
| A．motion | B．action | C．function | D．fact |
On the Eve of the Spring Festival, we Chinese people like to play with fireworks, and the noise doesn’t ________ until after midnight.
| A．die from | B．die off | C．die out | D．die down |
The children, ________ had played the whole day long, were worn out.
| A．all of what | B．all of which | C．all of them | D．all of whom |
We are confident that the environment ________ by our further efforts to reduce pollution.
| A．improves | B．will be improved | C．has improved | D．was improved |
— Where did you find the professor who made the speech yesterday?
— It was in the hall_______ the students often have a meeting.
| A．where | B．which | C．that | D．when |
When I first met Mary I didn’t like her, but I ________ my mind.
| A．have changed | B．change | C．had changed | D．would change |