Focus
From source to tap: it’s a long way
Urban residents take tap water for granted. But the process of feeding clean, safe water into their houses is complicated.
Pollution at source
Major sources of tap water include groundwater, lakes, rivers and water reserves.
- 对本期电子报订户、有效期内的VIP教师会员和本学期二十一世纪英文报尊享卡用户，我们开放所有内容：
- 如果您拥有以上权限，请点这里登录；
- 订阅电子报，请点这里；
- 激活VIP教师卡，请点这里；
- 激活21英语尊享卡，请点这里。
