Ⅰ. 根据语境写出正确的单词
1. cause severe diarrhoea 引起严重的腹泻
2. become frustrated 变得沮丧
3. two contradictory theories 两种相互矛盾的理论
4. an infection from germs 感染了细菌
5. need proof 需要证据
6. multiple deaths 很多人死亡
7. many poor households 很多贫困家庭
8. suspect him of theft 怀疑他盗窃
9. through this intervention 通过这种干预
10. raw waste 未经处理的废弃物
11. pure water 纯净水
12. a substantial decrease 大幅降低
13. use of maps and statistics 地图和统计数据的使用
14. transform the way 改变方式