What are their jobs ? 这句话中主语是“their jobs”那么系动词为什么用复数are ?

What are their jobs ? 这句话中主语是“their jobs”那么系动词为什么用复数are ? what are their jobs? their,are,what,jobs?连词成句 What are their jobs?同义句 what are their jobs怎么读 What are their jobs?为什么要用their而不能用they? 连词成句 jobs are what they'are drivers their(?.) what are their jobs?They are _____(milkman) 请问新概念第一册17课中有一句话是What are their jobs?,这句中的their我 What are their jobs?的答句是什么? What are their jobs?These wormen are____A wives B housewife they are very busy,what are their jobs说what is their job可以么