Snowmaking machines work by spraying a mist that freezes immediately on contact with cold air. Because the sudden freezing kills bacteria, QuickFreeze is planning to market a wastewater purification system that works on the same principle. The process works only when temperatures are cold, however, so municipalities using it will still need to maintain a conventional system.

Which of the following, if true, provides the strongest grounds for a prediction that municipalities will buy QuickFreeze's purification system despite the need to maintain a conventional purification system as well?

 A Bacteria are not the only impurities that must be removed from wastewater.

 B Many municipalities have old wastewater purification systems that need to be replaced.

 C Conventional wastewater purification systems have not been fully successful in killing bacteria at cold temperatures.

 D During times of warm weather, when it is not in use, QuickFreeze's purification system requires relatively little maintenance.

 E Places where the winters are cold rarely have a problem of water shortage.

  申友解析

题干：先讲低温杀菌消毒原理，接着说QF公司的净水系统是基于同样的原理，同时考虑到该系统只能在低温环境下工作，所以市政部门仍然需要维持传统净水系统。

题目：下面哪个选项为“市政部门在维护传统净水系统的同时会购买QF的净水系统”这个预测提供了最强有力的论据。

分析：题干和问题中的关键对象是QF的净水系统，关键属性是低温条件下可杀菌消毒。题目考察的逻辑方向是补充型引入他因正向逻辑，所以答案的逻辑方向一定是讲QF净水系统的正面属性同时要考虑到维持旧系统的必要性。

A选项引入无关对象；

B选项同样讨论无关对象，仅仅考虑到旧系统需要被更换无法说明是否需要采购QF的新产品；

C选项正确；

D选项：一方面提到天气炎热的情况下无法使用新系统，一方面讨论QF系统在空闲时维护成本很低；

E无关对象的无关属性。