1. Factors affecting general health include excessive smoking and drinking of alcohol and polluted water supplies.
    影响大众健康的因素包括吸烟过度、酗酒以及饮水污染。

2. For example, the amount of water on Earth is limited; this water is cleaned through natural processes.
    比如说，地球上的水量是有限的，这些水通过自然作用得到净化。

3. Fresh roses are sprayed with water to keep them moist and flown to company stores three times a week.
    新鲜的玫瑰经过洒水保湿后，每周三次空运到公司各个分店。