New words and phrases:climb 爬careful 小心的,仔细的dangerous 危险的touch 触摸,碰 play with fire 玩火downstairs往楼下 祈使句的否定形式Dont+V+NDont open the window.Dont play the computer games.Dont climb.Dont play with the fire.Dont sit on the desk.Dont climb the tree.Dont run downstairs.Dont play with the fire.Dont touch it.Dont stand on the chair.Dont touch it.Dont smoke.