题目

Gmat 逻辑题,OG的498页,逻辑43题~
Installing scrubbers in smokestacks and switching to cleaner-buring fuel are the two methods available to Northern Power fro reducing harnful emissions from its plants.Scrubbers will reduce harmful emissions more than cleaner-buring fuels will.Therefore,bu installing scrubbers,Northern Power will be doing the most that can be done to reduce harmful emissions from its plants.
which of the following is an assumption on which the argument depends?
A.Switching to cleaner-burning fuel will not be more expensive than installing scrubbers.
B.Northern Power can choose from among various kinds of scrubbers,some of which are more effective than others.
C.Northern Power is not necessariliy committed to reducing harmful emissions from its plants.
D.Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone.
E.Aside from harnful emissions from the smokestacks of its plants,the activities of Northern Power do not cause signifucant air pollution.

提问时间：2021-04-01

答案

安装scrubber的效果比cleaner好,所以,工厂就应该安装S.
这是一道假设题,对选项除非如果是削弱原文,那么该项就是答案.
这里包含了一个错误的解释,为什么一定要二选一 ,两个都选可能效果更好,而D选项就是排除这种可能,只有这样才能说明安装S能最大程度减排.
所以选D