Unit 1 Public signs单元知识要点：词汇： No smoking, No littering, No parking, No cycling, No eating and drinking, keep off, Dont touch, keep quiet, make noise, walk on the grass, public signs, only four years old, take a walk, ask some questions, stay away from, on the birds cage, pick up, ride a bike, take photos, climb the tree, come up, look around, a ten-yuan note 句型：What does this/that sign mean? It means Danger.You shouldnt make noise/park/eat and drink/.You
