He was having dinner____a unknown woman knocked at the door.填when还是while?
问题描述：
He was having dinner____a unknown woman knocked at the door.填when还是while?
答
whenwhywhen表示就在这时，发什么。。。，表示突然、意外可以while也有这种用法啊while，没有它只是表示伴随，没有意外的成分