不一定 要看回到的主语是什么
但是提问的时候who 后面是一定要用单数形式
eg.Who is playing in the garden?Lucy and Lily are playing in the garden.
Who is not here?Jack and Jim are not here.
Who wants to have a try?I want to have a try.
Who does the housework everyday?My mother and my sister do the housework everyday.