狒狒46

Justinchen01

46. Twelve healthy volunteers with the Apo-A-IV-1 gene and twelve healthy volunteers who instead have the Apo-A-IV-2 gene each consumed a standard diet supplemented daily by a high-cholesterol food. A high level of cholesterol in the blood is associated with an increased risk of heart disease. After three weeks, the blood cholesterol levels of the subjects in the second group were unchanged, whereas the blood cholesterol levels of those with the Apo-A-IV-1 gene rose 20 percent.

 

Which one of the following is most strongly supported by the information above?

 

A.        Approximately half the population carries a gene that lowers cholesterol levels.

B.        Most of those at risk of heart disease may be able to reduce their risk by adopting a low-cholesterol diet.

C.        The bodies of those who have the Apo-A-IV-2 gene excrete cholesterol when blood cholesterol reaches a certain level.

D.       The presence of the Apo-A-IV-1 gene seems to indicate that a person has a lower risk of heart disease.

E.        The presence of the Apo-A-IV-2 gene may inhibit the elevation of blood cholesterol.

我对C有疑问，反而感觉E没关系。

Justinchen01

是不是C和题干的支持和别支持搞反了？而E中一个may字表明是可能得出的结论呢？是这样理解吗？请达人指点！

rationalusa

C说反了，excrete是分泌的意思，when blood cholesterol reaches a certain level，还分泌胆固醇，怎么可能会使最后的实验比较效果成立：第二组的胆固醇LEVEL不变？

E选项说inhibit the elevation of blood cholesterol，抑制胆固醇进一步升高，恰好说明了题目中的情况。两组人在consumed a standard diet后会出现不同的情况，说明第二组人可能有什么可以抑制胆固醇升高效力的能力，恰好文中强调的就是两组人的基因不同，可见第二组人的基因可能有某种特殊效力。E表达了这样一个意思。

另外，E选项是根据原文内容可以在合理范围内推理出来的。C的信息是无关选项，因为原文没有提到任何关于两种基因是否有分泌何种物质的作用。注意此题是一个归纳题，任何超出题目本身描述的自加信息都是错误的。

Justinchen01

一看ls的就是NN，哈哈！

我之前以为excrete是排除体外而不是就渗透blood里呢。

Raymond_GMAT

我也把excrete的意思理解错了，似乎还觉得C中的reaches a certain level.和题目中的cholesterol levels of the subjects in the second group were unchanged相呼应。

犹豫了半天，还是选错了。