20. The wild mouflon sheep of the island of Corsica are direct descendants of sheep that escaped from domestication on the island 8,000 years ago. They therefore provide archaeologists with a picture of what some early domesticated sheep looked like, before the deliberate selective breeding that produced modern domesticated sheep began.

The argument above makes which of the following assumptions?

(A) The domesticated sheep of 8,000 years ago were quite dissimilar from the wild sheep of the time.

(B) There are no other existing breeds of sheep that escaped from domestication at about the same time as the forebears of the mouflon.

(C) Modern domesticated sheep are direct descendants of sheep that were wild 8,000 years ago.

(D) Mouflon sheep are more similar to their forebears of 8,000 years ago than modern domesticated sheep are to theirs.（D）

(E) The climate of Corsica has not changed at all in the last 8,000 years.

答案D。请问D取非如何使原argument不成立，谢谢！

原文:M羊比现在的羊跟想古羊.取非:M羊最多和现在的羊一样想古羊.从取非来看,现在的羊也可以提供这样的picture而且说不定比M羊跟适合,从而weaken结果.

假如这种野生的还不如现在家养跟以前家养的接近，那就用现在家养的研究

好啦。也就weaken 了

They therefore provide archaeologists with a picture of what some

early domesticated sheep looked like, before the deliberate

selective breeding that produced modern domesticated sheep began.

不过我感觉这个题目的conclusion其实写的有点不严密。如果改成they

provide better evidence than..... about how ......感觉会比较好一点。