Who are they waiting for?(划线部分为 their mum )

【俊狼猎英】团队为您解答.I‘m astudent.（一般疑问句）Are you a student?Dancooksdinnerinthekitchen.（提问）Where does Dad cook dinner?(对in the kitchen 提问)对不起，是对（cooks dinner）提问What does Dad do in the kitchen?