Question

A medical study has shown that excess(过度的)coffee drinking could cause heart attacks in people who do not metabolize(使新陈代谢)caffeine fast enough.

The study, published recently in the Journal of the American Medical Association, says an enzyme(酶)that metabolizes caffeine in the liver works differently in some people, depending on the make­up of the gene(基因). People who have a slow version (版本)of the enzyme are at a greater risk(风险)of a heart attack when they drink more coffee. The risk had something to do with a person's age and how many cups of coffee he drinks.

The team from the University of Toronto in Canada studied 4,024 people living in coffee­rich Costa Rica between 1994 and 2004, of whom half suffered non­fatal(非致命的)heart attacks. They found slightly more than half had the slow version of the gene, while the rest had the fast form.

Two to three cups of coffee a day increased the possibilities of a heart attack by 36 percent for those with the slow­acting gene and four or more cups a day lifted it by 64 percent.

But those under 50 who had the fast version of the gene had a lower risk of heart disease, even with four or more cups a day.

Those with the fast­acting gene who drank two to three cups of coffee a day had 22 percent reduced possibilities of having a heart attack, but drinking four or more cups a day only lessened the risk by 1 percent. Scientists recommend limiting coffee consumption(消耗量)to within four cups a day.

1.People who have a slow version of the enzyme________.

A. are in danger when they drink coffee    B. are living in coffee­rich Costa Rica

C. have the slow version of the gene    D. can not drink four or more cups of coffee a day

2.The example of Costa Rica the author presented in the passage proves that________

A. the heart attack in Costa Rica is really serious.

B. the heart problem has something to do with drinking coffee.

C. people in Costa Rica cannot metabolize caffeine in the liver.

D. more than half people have the slow version of gene.

3.It can be concluded that the passage is most probably written for________

A. doctors who study heart disease

B. specialists who offer medical care

C. old people who have the slow version of the gene

D. those who love drinking coffee every day

4.What is the best title for this passage?

A. Coffee and heart attacks    B. Gene and heart disease

C. Caffeine and enzyme    D. Reasons for heart problems

Answer

1. C

2. B

3. D

4. A

【解析】

本文是一篇说明文。文章讲述的是咖啡和心脏病之间的关系。

1.细节理解题。根据第二段People who have a slow version (版本)of the enzyme are at a greater risk(风险)of a heart attack when they drink more coffee. 和第三段中They found slightly more than half had the slow version of the gene, while the rest had the fast form.可知，有慢版本酶的人有慢版本的基因。故选C。

2.推理判断题。根据第三段中People who have a slow version (版本)of the enzyme are at a greater risk(风险)of a heart attack when they drink more coffee. The risk had something to do with a person's age and how many cups of coffee he drinks.和第四段中The team from the University of Toronto in Canada studied 4,024 people living in coffee­rich Costa Rica between 1994 and 2004, of whom half suffered non­fatal(非致命的)heart attacks.可知，作者在文中给出的哥斯达黎加的例子证明了心脏问题与喝咖啡有关。故选B。

3.推理判断题。根据第一段A medical study has shown that excess(过度的)coffee drinking could cause heart attacks in people who do not metabolize(使新陈代谢)caffeine fast enough.可知，这篇文章很可能是写给那些喜欢每天喝咖啡的人的。故选D。

4.主旨大意题。根据第一段A medical study has shown that excess(过度的)coffee drinking could cause heart attacks in people who do not metabolize(使新陈代谢)caffeine fast enough.可知，本文讲述的是咖啡和心脏病之间的关系。故选A。