天山 3-29 好心人可否帮忙回答

citidandan

The emission of sulfur dioxide
                    when high-sulfur coal is burned is restricted by law. New coal-burning plants usually comply with the law by installing expensive equipment to filter sulfur dioxide from their emissions. These new plants could save money by installing instead less expensive cleaning equipment that chemically removes most sulfur from coal before combustion.

 

Which of the following, if known, would be most relevant to evaluating the claim above about how new-coal burning plants could save money?

 

1. Whether existing oil-burning plants are required to filter sulfur dioxide from their emissions.

2. Whether the expense of installing the cleaning equipment in a new plant is less than the expense of installing the cleaning equipment in an older plant.

3. Whether the process of cleaning the coal is more expensive than the process of filtering the emissions

4. Whether lawful emissions of sulfur dioxide form coal-burning plants are damaging the environment.

5. Whether existing plants that use the filtering equipment could replace this equipment with the cleaning equipment and still complete with new plants that install the cleaning equipment.

结论为用cleaning equipment代替filter equipment可以save money，我选A。

if yes, 即无论如何filter都是required的，那代替与否都不能减少费用；if no，则可以代替，即减少费用

可答案为C；我认为clean the coal纯属新概念与原文无关啊

可否请好心人指点。。。Tks！

bandito

A错，oil-burning plants和题目有什么关系？

C正解，cleaning the coal恰恰是原文中所忽略的一个关键问题。安装这个cleaning装置可能比安装filter装置更便宜，但是使用起来呢？不一定了！C解决了这个疑惑。