In parts of South America, vitamin-A deficiency is a serious health problem, especially among children.  In one region, agriculturists hope to improve nutrition by encouraging farmers to plant a new variety of sweet potato called SPK004 that is rich in betacarotene, 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?

A. There are other vegetables currently grown in the region that contain more beta-carotene than the currently cultivated varieties of sweet potato do.

B. 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.

C. For successful cultivation of SPK004, a soil significantly richer in nitrogen is needed than is needed for the varieties of sweet potato currently cultivated in the region.

D. There are no other varieties of sweet potato that are significantly richer in beta-carotene than SPK004 is.

E. The currently cultivated varieties of sweet potato contain no important nutrients that SPK004 lacks.

答案选的是E

我选D

gwd的题目无E这个选项

大家能帮我解释下D为什么不可以嘛？？

谢谢大家啦

D has nothing to do with successful plan.

   能否再详细解释下，谢谢啦

GWD-1-Q15跟这个题干一样，选项不同。出题的家伙好狡猾，把选项改一改就把我们弄晕了。不过LZ问的D选项跟这个题里的C是一样的，都是错的。

因为：其它东西里含的beta-carotene 比SPK004多不多跟题目无关，因为只要SPK004比现在种的sweet potato里含的beta-carotene 多就可以了。所以，这种错误类型叫做无关比较

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?

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.

answer : A.

E 现有的土豆不含有SPK004缺少的营养物质

怎么看怎么象无关项。。

d:说明了没有有更好的添土豆，这并不能说明现在的plan不能成功，只是不一定是最好的plan

e：说明现在这个SPK004有营养上的缺陷

选E

有点明白了。。

这个E选项是说 这个品种的土豆没有的营养物质 其他土豆也没有  还比其他土豆多种物质帮忙转化维生素A   所以种这个土豆会提高国民身体素质 是这意思不????