GMAT OG2019全新出炉，欧米GMAT整理逻辑新题并附上解析，欧米官网已经更新完毕啦→逻辑新题解析
584. Enforcement of local speed limits through police monitoring has proven unsuccessful in the town of Ardane. In many nearby towns, speed humps (raised areas of pavement placed across residential streets, about 300 feet apart) have reduced traffic speeds on residential streets by 20 to 25 percent. In order to reduce traffic speed and thereby enhance safety in residential neighborhoods, Ardane’s transportation commission plans to install multiple speed humps in those neighborhoods.
Which of the following, if true, identifies a potentially serious drawback to the plan for installing speed humps in Ardane?
A. On residential streets without speed humps, many vehicles travel at speeds more than 25 percent above the posted speed limit.
B. Because of their high weight, emergency vehicles such as fire trucks and ambulances must slow almost to a stop at speed humps.
C. The residential speed limit in Ardane is higher than that of the nearby towns where speed humps were installed.
D. Motorists who are not familiar with the streets in Ardane’s residential districts would be likely to encounter the speed humps unawares unless warned by signs and painted indicators.
E. Bicyclists generally prefer that speed humps be constructed so as to leave a space on the side of the road where bicycles can travel without going over the humps.
题目大意
通过警方监控来实施当地强制限速在A地已被证明不成功。在附近几个城镇，减速带（铺设在住宅街道上的高架路面，相距约300英尺）使得住宅街道的交通速度降低了20-25%。为了降低交通速度并且提高住宅地区的安全性，A地的交通委员会计划在这些地区安装减速带。
解题思路
问题问下面选项如果是真的，哪个可以证明安装减速带的计划存在严重的缺陷，也就是削弱原文，说明安装减速带可能会引起其他不必要的问题。
A：在没有减速带的住宅街道，很多车的速度比之前限速的高25%。错，没有安装的地方速度高，那么安装的地方速度低，就说明减速带是有效的。
B：因为重量大，急救车辆比如消防车和救护车，遇到减速带就需要减速到几乎停止。正确，这样容易引发交通事故，也会妨碍这些急救车辆赶赴工作地点。
C：A地的住宅区限速高于附近安装了减速带的城镇。错，速度高低与原文无关，原文主要说的是安装减速带是否有缺陷。
D：不熟悉S地住宅区的驾驶员很可能会不知不觉的遇到减速带，除非有一些标记去警示他们。错，条件性的选项一般不能选，描述的比较特殊，而且条件成立和不成立会有两种结果。不熟悉路况的人应该不多，也不知道是不是本来就安装了警示物。
E：骑自行车的人一般都愿意修建减速带，这样就可以在路边留出一点空间让自行车通过，而不用直接走在减速带上。错，自行车与原文无关。
答案：B