In many cases inferior-quality, and often polluted, water supplies must be utilized to meet the demand . 在许多情况下，必须利用劣质以及常常是被污染的水源来满足需要。
Certain key aspects of abatement planning are best addressed through the use of an ambient air quality model . 消除污染的计划相当关键的方面最好通过应用环境模式来提出。
Another early approach to controlling exhaust emissions was the engine modification, or controlled-combustion system . 另一种早期的控制排气污染的途径是发动机调整或控制燃烧系统。
The quetions one must ask are how much does air pollution cost, and what expense is justified in rectifying it ? 人们一定要问空气污染的代价多大，为了改正它，要花多少才算是合理的？
Uncontaminated water is normally used as seal water for vacuum pumps and for compressor cooling as well as for sanitary use . 未污染的水通常用作真空泵的密封水和压缩机的冷却水以及供保健用。
According to this plan, the money we spent on meeting government safety and pollution standards would be refunded to us . 根据这个计划，我们为达到政府规定的安全和污染的标准而花掉的钱将退还我们。
One significant use of ion exchange treatment is for chromate contaminated blowdown from recirculating cooling water systems . 离子交换法的一个重要应用是用来处理铬酸盐污染的循环冷却水系统的排污。
One significant use of ion exchange treatment is for chromate contaminated blowdown from recirculating cooling water systems . 离子交换树脂的一个重要应用是用来处理铬酸盐污染的循环冷却水系统的排污。
All automobile engines now built are equipped with the positive-crankcase ventilation system of crankcase emission control . 所有现代制造的汽车发动机，都需要装备控制曲轴箱有害污染的曲轴箱强制通风系统。
In this country there is about a twofold difference in mortality for areas of high atmospheric pollution compared with the smoke-free rural areas . 在这个国家，大气高度污染的地区与没有烟尘的乡村比，死亡大约有两倍的差异。
