the discussion （）alive wehn an intersting topic was bought inA. was comingB. had comeC.has comeD.came(加解释）
问题描述：
the discussion （）alive wehn an intersting topic was bought in
A. was coming
B. had come
C.has come
D.came
(加解释）
答
选C因为翻译句子理解情景，讨论热烈开展起来当一个有趣的话题被引入的时候,引入话题是先发生的
答
A
一般过去时when前的句子是过去进行时