请教GWD-18，Q13

chunjie

Eurasian watermilfoil, a weed not native to Frida Lake, has reproduced prolifically since being accidentally introduced there.  In order to eliminate the weed, biologists proposed treating infested parts of the lake with a certain herbicide that is nontoxic for humans and aquatic animals.  However, the herbicide might damage populations of certain rare plant species that the lake contains.  For this reason local officials rejected the proposal.

 

Which of the following, if true, points out the most serious weakness in the officials' grounds for rejecting the biologists' proposal?

A	The continuing spread of Eurasian watermilfoil in Frida Lake threatens to choke out the lake's rare plant species.
B	Because of ecological conditions prevailing in its native habitat, Eurasian watermilfoil is not as dominant there as it is in Frida Lake.
C	The proliferation of Eurasian watermilfoil in Frida Lake has led to reductions in the populations of some species of aquatic animals.
D	Although Eurasian watermilfoil could be mechanically removed from Frida Lake, eliminating the weed would take far longer this way than it would using herbicides.
E	Unless Eurasian watermilfoil is completely eliminated from Frida Lake, it will quickly spread again once herbicide treatments or other control measures cease.

 

正确答案是A，为什么选A，而不是B？

286的幸福观

驱除EW，会用到有害的除草剂；因为这些除草剂可能使一些稀有植物绝种，所以官方反对。

题目是如何削弱官方的反对。

A说如果不除掉，EW继续生长将会使稀有植物窒息而死。不除EW，稀有植物也会绝种。

B对比native habitat没有意义，stimulus的焦点在于是否会危害稀有植物。

rice514

同意楼上的看法.B是无关比较, 把EW在原生存地和现在的做比较, 无关.

本题是要求WEAKEN "officials' grounds",也就是不用这种除草剂不会对稀有植物有害.A说明不用仍然有害. 因此就是A.