Q14:

Maize contains the vitamin niacin, but not in a form the body can absorb. Pellagra is a disease that results from niacin deficiency. When maize was introduced into southern LACE>EuropeLACE> from the LACE>AmericasLACE> in the eighteenth century, it quickly became a dietary staple, and many Europeans who came to subsist primarily on maize developed pellagra. Pellagra was virtually unknown at that time in the LACE>AmericasLACE>, however, even among people who subsisted primarily on maize.

Which of the following, if true, most helps to explain the contrasting incidence of pellagra described above?

1. Once introduced into southern LACE>EuropeLACE>, maize became popular with landowners because of its high yields relative to other cereal crops.
2. Maize grown in the LACE>AmericasLACE> contained more niacin than maize grown in Europe did.
3. Traditional ways of preparing maize in the Americas convert maize’s niacin into a nutritionally useful form.
4. In southern Europe many of the people who consumed maize also ate niacin-rich foods.
5. Before the discovery of pellagra’s link with niacin, it was widely believed that the disease was an infection that could be transmitted from person to person.

选C

那位可以解释　以下么？？

用粗而不俗的话来解释这段话就是：

一种老玉米含有一种vitamin，这种vitamin有两种特性：1.身体缺乏,得pellagra这种病 2.人体不能直接吸收。有两种人：美洲人和欧洲人。他们都吃这种老玉米，但美洲人没事，欧洲人得pellagra病了。问这是咋搞得？

这不禁让我们想起了广告：“补钙重在吸收”。C答案就是说它是怎么变得能够被吸收的。

这个题最烦人的是句子”Pellagra was virtually unknown at that time in the LACE>Americas”中unknown这个词。它有多个解释。1.发生了，但不清楚 2.以前没经历过的。这是两种截然不同的意思。在这里应该是第二种。LACE>

C说在美国，玉米的烹调方式使niacin变成nutritionally useful form.这可以理解为niacin能被身体吸收，所以就不缺niacin，与就不得P病，也就不会被发现。其他易排出.