求问36套中的exercise19两个问题~~

老张要高分UID：3508356

先把阅读和题目贴上来：
4. Which of the following most logically completes the argument?
Alivia‘s government has approved funds for an electricity-generation project based on the construction of a pipeline that will carry water from Lake Cylus, in the mountains, to the much smaller Lake Tifele, in a nearby valley. The amount of electricity generated will be insufficient by itself to justify the project‘s cost, even if the price of imported oil-Alivia‘s primary source of electricity-increases sharply. Nonetheless, the pipeline project is worth its cost, because ——

(A) the price of oil, once subject to frequent sharp increases, has fallen significantly and is now fairly stable
(B) the project could restore Lake Tifele, which is currently at risk of drying up and thus of being lost as a source of recreation income for Alivia
(C) the government of Alivia is currently on excellent terms with the governments of most of the countries from which it purchases oil
(D) it would cost less to generate electricity by moving water from Lake Cylus to lake Tifele than to do so by moving water from Lake Cylus to another valley lake
(E) Alivian officials do not expect that the amount of electricity used in Alivia will increase substantially within the next ten years
我选择的是B，因为我觉得文章是在比较用水发电和用油发电哪个更加理想。因为要证明用水发电更加好，所以B选项中的还有另外的娱乐收入会使得这个方法更加好。
不过这道题的答案是D。我个人不是很理解，因为我觉得文章并不是在比较运水的线路好坏。

Students of United States history, seeking to identify the circumstances that encouraged the emergence of feminist movements, have thoroughly investigated the mid- nineteenth-century American economic and social conditions that affected the status of women. These historians, however, have analyzed less fully the development of specifically feminist ideas and activities during the same period. Furthermore, the ideological origins of feminism in the United States have been obscured because, even when historians did take into account those feminist ideas and activities occurring within the United States, they failed to recognize that feminism was then a truly international movement actually centered in Europe. American feminist activists who have been described as ―solitary‖ and ―individual theorists‖ were in reality connected to a movement—utopian socialism— which was already popularizing feminist ideas in Europe during the two decades that culminated in the first women‘s rights conference held at Seneca Falls, New York, in 1848.
6. According to the passage, which of the following is true of the Seneca Falls conference on women‘s rights?
(A) It was primarily a product of nineteenth-century Saint-Simonian feminist thought.
(B) It was the work of American activists who were independent of feminists abroad.
(C) It was the culminating achievement of the utopian socialist movement.
(D) It was a manifestation of an international movement for social change and feminism.
(E) It was the final manifestation of the women‘s rights movement in the United States in the nineteenth century.
我选择的是C。我觉得根据最后一句话，这个utopian socialism的确是在这个会议中达到了最高点。
答案是D。我觉得也是正确的。但是我想知道为什么D会比C好

求各位大神指点~~！