unit 5  our environment
1、pollution on earth
2、priority given to the environment
3、improments in the surroundings
4、difficulty points in this unit
5、environment: all the circumstance,people,livings and events around them
6、the state environmental protection administration国家环保局
7、air quality空气质量 acid rain 酸雨
8、residue [res•i•due || 'rezɪduː /-dju-]n. 残渣, 余数, 剩余
9、toxic [tox•ic || 'tɑksɪk(l) /'tɒk-]adj. 有毒的, 中毒的
10、muggy [mug•gy || 'mʌgɪ]adj. 闷热的
11、symposium座谈会
12、sewerage排水设备