高一英语改错：On hearing us,they ran to the spot as fast as they could.
问题描述：
高一英语改错：On hearing us,they ran to the spot as fast as they could.
已经知道是把on改成after,就是想问为什么?
答
on doing 是一……就……的意思,感觉没多大问题、硬要改的话、参考答案可能牵强了
就是 他们一听到我们（到了）,就以最快的速度跑到了这个地方.
望采纳~