18.
A proposed ordinance requires the installation in new homes of

sprinklers automatically triggered by the presence of a fire.

However, a home builder argued that because more than ninety

percent of residential fires are extinguished by a household

member, residential sprinklers would only marginally decrease

property damage caused by residential fires.

Which of the following, if true, would most seriously weaken the

home builder’s argument?

A. most individuals have no formal training in how to extinguish

fires.

B. Since new homes are only a tiny percentage of available housing

in the city, the new ordinance would be extremely narrow in scope.

C. The installation of smoke detectors in new residences costs

significantly less than the installation of sprinklers.

D. In the city where the ordinance was proposed, the average time

required by the fire department to respond to a fire was less than

the national average.

E. The largest proportion of property damage that results from

residential fires is caused by fires that start when no household

member is present.

开始以为however之后的是结论部分，但是仔细看看觉得however之前是结论

。大家觉得呢？

我对题目的理解是：home builder认为，因为90%的火都是由家庭成员扑灭的，所以sprinklers只能在很小程度上降底火灾引起的财产损失。

e：最大比例的财产损失是因为最初着火的时候家里没有人

我怎么觉得e是加强不是消弱，55555，好困惑的说，谁知道的话，给解释解释，og的解释我看了半天也不明白。

题目不是写得很清楚home builder argued......这个当然是结论了。

楼主的困惑在于，到底加强谁削弱谁，题目说的是削弱home builder's arguement，也就是说削弱不安装，所以E当之无愧啦。

看题目的时候一定要看清楚到底weaken/strength who，这个WHO一般都在前面有具体替代的，找到替代就可以了。