GWD-1-15

Q15:

In parts of South America, vitamin-A deficiency is a serious health problem, especially among children.  In one region, agriculturists are attempting to improve nutrition by encouraging farmers to plant a new variety of sweet potato called SPK004 that is rich in beta-carotene, which the body converts into vitamin A.  The plan has good chances of success, since sweet potato is a staple of the region’s diet and agriculture, and the varieties currently grown contain little beta-carotene.

Which of the following, if true, most strongly supports the prediction that the plan will succeed?

1. The growing conditions required by the varieties of sweet potato currently cultivated in the region are conditions in which SPK004 can flourish.
2. The flesh of SPK004 differs from that of the currently cultivated sweet potatoes in color and texture, so traditional foods would look somewhat different when prepared from SPK004.
3. There are no other varieties of sweet potato that are significantly richer in beta-carotene than SPK004 is.
4. The varieties of sweet potato currently cultivated in the region contain some important nutrients that are lacking in SPK004.
5. There are other vegetables currently grown in the region that contain more beta-carotene than the currently cultivated varieties of sweet potato do.

答案是A，可我认为C更正确。请赐教。THANKS~

文章要说措施可行，也就是spk能够最终取代现在的那堆玩意儿。A说spk能种的好，而且又比原来有益，农民显然会种，措施可行+强；C说没有其他玩意儿比spk含bc多，文章说spk，这里蹦出个other品种显然无关。

恩，我同意你说的选A的理由，最开始我也把A作为备选项，但是看到C了后就可以根据文中陈述内容反推，The plan has good chances of success因为1.sweet potato is a staple of the region’s diet and agriculture,2. the varieties currently grown contain little beta-carotene.如果有其他的SWEET POTATO比SPK含更多的beta-carotene，那农民很可能就种其它的种类了，这个plan就不一定成功，但C排除了上述可能，所以我才认为选C更恰当。是不是我思路错了？

应该是吧，文章首先说是农业学家要尝试改良品种，他们看到了一种胡萝卜素缺乏，所以倡议改良品种，而不是农民本身要改良品种，如果农业学家不倡议spk农民们没准儿继续种原来的，c谈到没有其他甜马铃薯比spk含有更多B胡萝卜素，这个跟文章本身的目的没有关系，倡导种spk就看种spk是否可行。不知道能明白么