I saw our math teacher talking with John when I _____ (pass) his _英语解答

I saw our math teacher talking with John when I _____ (pass) his office.
请问这个地方为什么不填passing而是passed呢?

人气：137 ℃　时间：2019-08-23 09:42:32

解答

一般由When引导的时间状语不用进行时, 再说了,如果你用passing 还少了个was, was passing构成过去进行时
中文意思: 当我经过数学老师办公室时, 我看见他在和约翰谈话