6AUnit 6 Keep our city clean 单元知识归纳一、词组1. keep our city clean保持我们的城市整洁 2. look at these pictures of our city看我们城市的这些图片3. make our city dirty 使我们的城市变脏 4. smoke from cars汽车尾气5. make the air dirty使空气变脏 6. black smoke from factories来自工厂的黑烟 7. make the streets messy使街道变乱 8. in the water在水里9. take the bus and the metro to school乘公共车和地铁上学 10. walk to school走路上学11. move some factories away把工厂搬走 12. put rubbish in the bin把垃圾放进垃圾箱13. plant more trees种更多的