心好累。。。求教og一道题

小陈冲鸭

In Colorado subalpine meadows, nonnative dandelions co-occur with a native flower, the larkspur. Bumblebees visit both species, creating the potential for interactions between the two species with respect to pollination. In a recent study, researchers selected 16 plots containing both species; all dandelions were removed from eight plots; the remaining eight control plots were left undisturbed. The control plots yielded significantly more larkspur seeds than the dandelion-free plots, leading the researchers to conclude that the presence of dandelions facilitates pollination (and hence seed production) in the native species by attracting more pollinators to the mixed plots.

Which of the following, if true, most seriously undermines the researchers` reasoning?A Bumblebees preferentially visit dandelions over larkspurs in mixed plots.
B In mixed plots, pollinators can transfer pollen from one species to another to augment seed production.
C If left unchecked, nonnative species like dandelions quickly crowd out native species.
D Seed germination is a more reliable measure of a species` fitness than seed production.
E Soil disturbances can result in fewer blooms, and hence lower seed production.
     请问下B为什么不对？B不是提供了另外一种有可能的解释吗？因为原文的结论是by attracting more pollinators to the mixed plots，而B说的是pollinators can transfer pollen from one species to another，意思不是不一样吗

小陈冲鸭

先谢谢大家了！！

L.M.

这个题要weaken的是研究者的推论过程（reasoning）。也就是要找实验不能说明问题的原因。

我就直接借用OG18里的reasoning来说了。。。这个推论过程觉得他的实验中实验组和对照组的唯一区别就是有没有蒲公英（dandelion）。因此只要找出其他的没控制住的变量就能反驳这个推论了。

顺带，我觉得B是strengthen了结论，并不是给出了alternative explanation。。。授粉者能把两种不同植物的花粉混起来augment seed production，顶多也只是把为啥“attract了pollinator之后就会增加seed production”这个事情说的更详细了，并不是给出为啥production会增加的另一个理由。

但正确答案E就不一样，它直接说了你研究者这个实验把人家根给挖啦，人家当然不开花也就不结果咯。也就是把产量的difference归因给了soil disturbance，跟蜜蜂啥的就没关系。

小陈冲鸭

L.M. 发表于 2018-10-14 16:20
这个题要weaken的是研究者的推论过程（reasoning）。也就是要找实验不能说明问题的原因。

我就直接借用OG1 ...

说的好清楚 谢谢啦

永远没多远

B 混种区，授粉昆虫能从在两个物种间授粉，增加种子产出；增强，方向反，排；
E 土壤翻动导致更少开花，因此更低的种子产出；他因削弱，正确

小陈冲鸭

永远没多远 发表于 2018-10-16 14:11
B 混种区，授粉昆虫能从在两个物种间授粉，增加种子产出；增强，方向反，排；
E 土壤翻动导致更少开花，因 ...

明白了 谢谢~