Betty's father and brother work in a factory.变成疑问句.
问题描述：
Betty's father and brother work in a factory.变成疑问句.
Does Betty's father and brother work in a factory?
为什么用的does,而不是do呢?
答
Do Betty's father and brother work in a factory?
主语是两个人Betty's father and brother'不可用DOES