I happened to be tolking with him when he was hit by a ball and collapsed.
问题描述:
I happened to be tolking with him when he was hit by a ball and collapsed.
为什么不填to talk?
答
后面的when he was hit by a ball and collapsed表示一个精确的时间点,前面应该用be talking表示在精确时间点正在发生的事情