13. No nation can long survive unless its people are united by a common tongue. For proof, we need only consider Canada, which is being torn asunder by conflicts between French-speaking Quebec and the other provinces, which are dominated by English speakers.

Which of the following, if true, most effectively challenges the author’s conclusion?

(A) Conflicts over language have led to violent clashes between the Basque-speaking minority in Spain and the Spanish-speaking majority.

(B) Proposals to declare English the official language of the United States have met with resistance from members of Hispanic and other minority groups.

(C) Economic and political differences, along with linguistic ones, have contributed to the provincial conflicts in Canada.

(D) The public of India, in existence sine 1948, has a population that speaks hundreds of different, though related, languages.（E）

(E) Switzerland has survived for nearly a thousand years as a home for speakers of three different languages.

DE之间想了很久。后来选了E。但请问D和E有何不同？是因为D有”though related”的原故吗?谢谢~~

这题的推理是

如果一个国家讲一种以上的语言，这个国家就不可能长期存在。

而D只是说，印度讲很多种语言，对文章推理没有任何作用，因而不是答案。

象这种题，是A——>B的推理，其削弱很多时候是有因无果的削弱。

E是说瑞典讲三种以上的语言，但国家去存在了一千多年。很典型的有因无果。

个人意见～～