While I TV the bell rang.A. watchB. watchedC. am watchingD. was watching

问题补充：

While I TV, the bell rang.

A. watch

B. watched

C. am watching

D. was watching

答案：

A. watch

B. watched

C. am watching

(答案→)D. was watching

解析：考查点：动词时态。解题思路：While一般情况下引导过去进行时。