Peter was about to unlock the door ___ he found someone had broken into the room.为什么要填WHEN,在这里是什么作用?

问题描述:

Peter was about to unlock the door ___ he found someone had broken into the room.
为什么要填WHEN,在这里是什么作用?

when是conj.就在这时候的意思

时间连接词啊

when 在这里是并列连词,意为“其时,就在这个时候”,用来引出一个意想不到的动作(下一分句中的动作)