how much is this book (改为同义句） 大名和玲玲正在那边等公共汽车.翻译

1.What's the price of this book?
2.Daming and Lingling are waiting for the bus over there.应填什么词？she says her room is very dirty and she ——to clean it.填 has 她说她的房间很脏她必须打扫。