Unit 6 Keep our city clean同步练习一、短语翻译。1.保持干净_____________________ 2.我们城市的这些图片_____________________3.汽车尾气_____________________ 4.工厂黑烟_____________________5.使空气变脏___________________ 6.又乱又脏_____________________7.在水里_____________________ 8.乘公交车_____________________9.步行去_____...