When the bell____(ring),Tom was dressing.为什么填rang而不填was ringing呢?

问题描述:

When the bell____(ring),Tom was dressing.
为什么填rang而不填was ringing呢?

因为是强调在铃铛响的时刻Tom在跳舞,不是说铃铛一直想,Tom一直在跳舞.语法两个都没问题,要靠翻译