2017年6月英语四级考试：仔细阅读练习(1)

距离2017年6月英语四级考试还有10多天，考前多做练习，查漏补缺才是王道，下面是新东方网英语四级频道为大家整理的英语四级阅读仔细阅读练习，并附答案，希望考生们抓紧复习。

There is evidence that the usual variety of high blood pressure is, in part, a familial disease. Since families have similar genes as well as similar environments, familial diseases could be due to shared genetic influences, to shared environmental factors, or to both. For some years, the role of one

environment factor commonly shared by families, namely dietary salt (i.e., sodium chloride), has been studied at Brookhaven National Laboratory. These studies suggest that long excess salt intake can lead to high blood pressure in man and animals. Some individuals, however, and some rats consume large amounts of salt without developing high blood pressure. No matter how strictly all environmental factors were controlled in these experiments, some salt-fed animals never developed hypertension whereas a few rapidly developed very severe hypertension followed by early death. These marked variations were interpreted to result from differences in genetic constitution.

By mating long successive generations of those animals that failed to  develop hypertension from salt intake, a resistant strain (the " R" strain) has been evolved in which consumption of large quantities of salt fails to influence the blood pressure significantly. In contrast, by mating only animals that quickly develop hypertension from salt, sensitive strain (the "S" strain) has also been developed.

The availability of these two strains permits investigations possible. They provide a plausible laboratory model on which to investigate some clinical aspects of the human hypertension. More important, there might be the possibility of developing methods by which genetic susceptibility (敏感性) of human beings to high blood pressure can be defined without waiting for its appearance. Radioactive sodium 22 was an important "tool" in working out the characteristics of the sodium chloride metabolism.

21. The study of the effects of salt on high blood pressure was carried out_______.

A. as members of the same family tend to use similar amounts of salt

B. to explore the long-term use of a sodium based substance

C. because it was proven that salt caused high blood pressure

D. because of the availability of chemically pure salt and its derivatives

22. The main difference between "S" and "R" rats is their_______.

A. need for sodium 22 B. rate of mating

C. reaction to salt D. type of blood

23. We can infer from the article that sodium 22 can be used to_______.

A. control high blood pressure

B. cure high blood pressure caused by salt

C. tell the "S" rats from the "R" rats

D. determine what a sodium chloride metabolism is like

24. The most beneficial results of the research might be_______.

A. development of diets free of salt

B. an early cure for high blood pressure

C. control of genetic agents that cause high blood pressure

D. the early identification of potential high blood pressure victims

25. Which of the statements best relates the main idea of this article?

A. When salt is added rats and human beings react similarly.

B. The near future will see a cure for high blood pressure.

C. The medical field is desperately in need of research.

D. A tendency toward high blood pressure may be a hereditary factor.

参考答案：21. A 22. C 23. D 24. D 25. D

英语四级备考每周精选推荐：6月第一周模拟试卷新东方2017.6英语四级考试模拟试卷及答案（5.25）英语四级考试模拟试卷及答案（5.24）四级考试模拟试卷及答案（5.31)2017年6月英语四级考试模拟试卷及答案新东方2017.6英语四级考试模拟试卷及答案（5.26）作文四级作文模板及范文汇总四级作文万能句型八类四级作文开头六大写法四级作文万能开头句式汇总四级作文常用的70个短语四级看图作文万能模板四级作文范文50篇四级作文常用加分谚语听力四级听力四大提分攻略英语四级听力提高四个方法四级听力篇章四类常考场景四级听力长对话解题技巧四级听力长对话解题窍门四级听力裸考猜答案技巧四级听力九大技巧汇总四级听力常考十三类场景词汇阅读四级阅读理解100篇精析汇总四级阅读长篇阅读技巧大学四级阅读技巧英语四级阅读理解技巧四级阅读选词填空三大解题技巧四级阅读理解常用句型四级阅读理解解题技巧四级阅读裸考必知10点翻译英语四级翻译每日一练汇总英语四级翻译题库大学四级翻译技巧四级段落翻译技巧四级翻译常用句型汇总四级段落翻译练习汇总 英语四级翻译技巧十九个定语从句四级翻译练习词汇四级词汇高效记忆训练汇总四级高频单词300个汇总570个英语四级高频词汇下载四级高频词汇584个汇总四级高频词汇及例句汇总四级活跃词汇1000个汇总 英语四级易混淆词汇整理50个句子记完7000个单词语法大学英语四级语法大全目录英语四级语法点集锦四级语法巩固练习100题 四级9种常用时态语法归纳