大全-1-12 (Gmat Test1-12): help! help! Please~~

12. Using computer techniques, researchers analyze layers of paint that lie buried beneath the surface layers of old paintings. They claim, for example, that additional mountainous scenery once appeared in Leonardo da Vinci’s Mona Lisa, which was later painted over. Skeptics reply to these claims, however, that X-ray examinations of the Mona Lisa do not show hidden mountains.

Which of the following, if true, would tend most to weaken the force of the skeptics’ objections?

(A) There is no written or anecdotal record that Leonardo da Vinci ever painted over major areas of his Mona Lisa.

(B) Painters of da Vinci’s time commonly created images of mountainous scenery in the backgrounds of portraits like the Mona Lisa.

(C) No one knows for certain what parts of the Mona Lisa may have been painted by da Vinci’s assistants rather than by da Vinci himself.

(D) Infrared photography of the Mona Lisa has revealed no trace of hidden mountainous scenery.（E）

(E) Analysis relying on X-rays only has the capacity to detect lead-based white pigments in layers of paint beneath a painting’s surface layers.

I can't see why the answer is E. I think if E is right, another assumption that Leonardo da Vinci didn't use lead-based white pigment when he created the mountanious scenery must be added into the reasoning. But we can not add such an assumption by ourselves if it is not mentioned in the question.

Can anyone help me make it clear? Many thanks.

我是这么理解的：

一种计算机技术认为，画有好几层，在L的画中可以看到以前的山水风景。反对观点认为；X射线没有看到山水画

找削弱，就是要找反对观点错的选项

A 没有记录现实     无知选项错

B。那个时代有人画山水  无关选项

C。没有人知道     无知选项错

d 有种东西也没有探测到山水    支持

E x射线只能探测到layers中的一层    削弱  指出 x的这种方法的不足

weaken 和assumption是不同的，只要搭边就可以啦

谢谢楼上MM回贴。但是，如果E只说“X-ray只能探测到lead-based white pigment“而没说“在Leonardo的那个年代没有这种lead-based white pigment “的话，我就觉得E还是有问题。假如在Leonardo的那个时代画家都用lead-based white pigment，而且Leonardo本人在作画时也经常使用lead-based white pigment，但是在《蒙娜丽莎微笑》里X-ray却没探测到，那E又可以support skeptics的结论说，《蒙娜丽莎微笑》底下就是没有山水画了。所以，只靠E本身不足以削弱。

请继续指教……

同意gmat700+

请教大家!!

Thanks a lot !!

one good lesson !!

谢谢斑竹指点。但是，按照你说的，我觉得B也可以作为“weaken”的答案了吧？为什么不对呢？

不好意思，我资质愚鲁， 还请mindfree进一步指点。

Good question.

B looks like an answer. However, it does not tie to the argument. The critics argue by referring to the fact that X ray could not detect the image. We can weaken the argument by E. B generally strengthens the researcher's position. But it does not weaken the opponent's argument because it is irrelevant to such argument.

Oh, I see. I just found I have too many things to dig out in such "weaken" question.

Thank you very much, mindfree.