The Whites were having dinner --(since,when,before,while)(选1

while peter's mother __was cooking___(cooked,was cooking),he (anseered） a telephone from Jack
当皮特的妈妈在做饭的时候,他接了一个杰克打来的电话.
The Whites were having dinner __(since,when,before,while)(选1）
选择when,表示,当某事正在进行时,另外一件事情也发生~~
比如The Whites were having dinner when someone knocked the door.
当怀特一家在吃饭时,有人敲门~