It began to rain I was walking in the park.A. until B. becauseC. whileD. although

问题补充：

It began to rain I was walking in the park.

A. until

B. because

C. while

D. although

答案：

A. until

B. because

(答案→)C. while

D. although

解析：句意：当我正在公园散步期间天开始下雨了。分析：下雨的时间是我正在公园散步的时候，是一个延续性的动作，因此用while. 故选C