听力音频：
https://mp.weixin.qq.com/s/VZKj1UaJ6n_3cXO8pM_KOA
Task1
Many regions in the world face problems with air pollution. What can be done to
decrease the amount of air pollution in these areas? Use details and examples in your
response.
Task2
Limit on Number of Library Books
Currently, students can take out as many books from the library as they want. But I think the library should limit the number of books students can take out at one time to ten. This will prevent students from checking out more books than they need. Sometimes, students take out additional books and never use them. In addition, this plan should help reduce the number of lost books each year. Students often have a hard time keeping track of large numbers of library books, and they often get misplaced.
Sincerely,
Bill Nash
Task3
Limit on Number of Library Books
Currently, students can take out as many books from the library as they want. But I think the library should limit the number of books students can take out at one time to ten. This will prevent students from checking out more books than they need. Sometimes, students take out additional books and never use them. In addition, this plan should help reduce the number of lost books each year. Students often have a hard time keeping track of large numbers of library books, and they often get misplaced.
Sincerely,
Bill Nash
Task4
范文：
