GWD-13-31

Q31:

By competing with rodents for seeds, black ants help control rodent populations that pose a public health risk.  However, a very aggressive species of blank ant, the Loma ant, which has recently invaded a certain region, has a venomous sting that is often fatal to humans.  Therefore, the planned introduction into that region of ant flies, which prey on Loma ants, would benefit public health.

Which of the following, if true, most strengthens the argument?

A.    Ant flies do not attack black ants other than Loma ants.

2. Loma ants are less effective than many bird species in competing with rodents for seeds.


3. Certain other species of black ants are more effective than Loma ants in competing with rodents for seeds.


4. The sting of Loma ants can also be fatal to rodents.


5. The use of pesticides to control Loma ants could have harmful effects on the environment.

答案A, 我选E,  排除它因加强，  A无关, 没有涉及would benefit public health

请NNs指正

upup

觉得你的思路有点不太对。

E项“harmful effects on the environment”未涉及需要证明的结论“benefit public health”。跑到环境上了，有点远吧。而且题目中的条件都用不上了。

A项很清楚，L蚁死，一般B蚁无影响，仍然可控制有害rodents，对人类有益。

这也是题排除他因的典型题

ant flies 如果会吃其他的ant 那就有助于rodents的成长 对public health 就有危害

A排除了这个可能 进而strengthens the argument

E和原文的论点没有多大关联 我觉得E才是无关

第二遍看觉得还是A。

L蚁对人有害，消灭就是beneficial。普通B蚁也对人有益。明显是加强。

E只说杀虫剂可能对环境有害，但没有说其对ant flies计划的作用，不知道其对L蚁和B蚁分别的作用。

答岸是A,E讲的是对环境有利,离题了。

除Lema以外的black ants 对人类有益

Lema对人类不利，

antflies只吃lema，消除了不利因数，又没有削减有利因素，所以对人类有益。

我对这句不理解black ants help control rodent populations that pose a public health risk

看你们的意思是rodent对公众有害对吧？可是你看看that修饰的是谁啊。rodent不是中心词，如果要that指代也是指代population，逻辑不通了。

我是以为that指代black ants这样就是黑蚂蚁给公众健康带来危险吧？所以A也有点问题啊：它不杀对公众有害的黑蚂蚁成削弱了吧？？？

请教

你是不是看错了，E 中是：have harmful effects on the environment.， 怎么能加强？