How old are the twin's?哪错了?

改错：How old are the twin's? How old are the twin's?哪错了? How old are your twin brother? By the way how old are you How old are the twins改错 what are the ...(twin) names? how old are you “How old are you? how old are you how old are How old are you? ( how old are How old are :How old are you? How old are you? The twin 后面是is还是are? these bikes are the ____(twin) these are the --------1 twin bag 2 twin's bag 3 twin's bag 4 twin's bags