GWD-13-31

queeniemai

GWD-13-31 

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.

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

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

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

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

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结论是Therefore, the planned introduction into that region of ant flies, which prey on Loma ants, would benefit public health.

public health risk形成，由于black ants competing with rodents，（pose没有反对的意思吧？）

而loma ant的到来，会影响public health。

所以introduce the ants flies，以benefit public health。

答案是A。

如果ants flies只影响Loma ants，那么对hunman的影响减少，benefit public health。但是前面black ants造成的risk还在呀！

我选了D。

这种sting对rodents也是fatal，那么就会减少上文提到的risk。而这种ants flies的到来，使得两种risk都减少，both to the risk and to hunman beings ,so public health 得到benefit。

或者a very aggressive species of blank ant, the Loma ant，这里应该是black ant instead of blank one？

请NN们指点！谢谢

won872

Therefore, the planned introduction into that region of ant flies, which prey on Loma ants, would benefit public health.

The author is most concern with the benefit of public health.

 

There are two threats to public health: 1) rodent 2) Loma ant, human is risk of dieing.

 

If the ant flies we plan to introduce can prey the Loma ant without harming the other innocent black ant which pray on the rodents which also posit harm to human being, we are benefit from a scenario, that is, one stone kills two birds.

 

 The sting of Loma ants can also be fatal to rodents. Black ant kill rodent any way, so whether the sting was fatal to rodent does not matter. However, it has not precluded the potential consequence of ant flies to many other kinds of harmless black ant to human being. If the ant flies pray on innocent ants, many of them would die at the expense of reduction in majority of pray to rodent, since Loma is only one of may kinds of black ant.

queeniemai

Got it~!!

I misunderstood the "black ants help control rodent populations that pose a public health risk"here.pose a public health risk is resulted from the rodent,rather than the black ants.

So if the ant flies prey on Loma ants,the rest of the black ants could still make a balance with the rodents.So the conclusion is strenghtened.

Many thanks to LS

won872

I agree "Be concentrated once you decide to do it !"