yesterday i was just about to go out -- someone telephoned me A,When B,while c,as 选哪个,为什么
问题描述：
yesterday i was just about to go out -- someone telephoned me A,When B,while c,as 选哪个,为什么
答
A. when正在这时的意思
答
A
一个固定的句式,be about when,意思是正准备干什么,突然怎么了