A cat it is a white one a black one is considered to be a good cat as long as it can c

问题补充：

A cat, it is a white one a black one, is considered to be a good cat as long as it can catch mice.

A. both; and

B. not only; but also

C. either; or

D. whether; or

答案：

A. both; and

B. not only; but also

C. either; or

(答案→)D. whether; or

解析：句意：一只猫不管是白猫还是黑猫，只要抓住了老鼠就是好猫。A……和……都B不仅……而且。C或者，或者D不管，还是，根据句意及结构，故选D。