The number of women dying from breast cancer has fallen to its lowest level ____ records began in 1971.
| A．when | B．before | C．since | D．after |
Bears __________ fat stores throughout the summer and fall to have energy enough to last them through their winter sleep.
| A．pack up | B．build up |
| C．bring up | D．take up |
-Do you have an __________ way to solve this problem?
-No, this is the only way, I think.
| A．alternative | B．urgent |
| C．absolute | D．equal |
One third of the country __________ covered with trees and the majority of the citizens __________ black people.
| A．is; are | B．is; is |
| C．are; are | D．are; is |
Japan's refusal to release __________ Chinese fishing boat captain had already caused __________ damage to Sino-Japanese bilateral contacts （双边关系）.
| A．the; 不填 | B．a; 不填 |
| C．a; a | D．the; the |
William found it increasingly difficult to read, for his eyesight was beginning to __________.
| A．disappear | B．fall |
| C．fail | D．damage |