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

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

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.

21. A 22. C 23. D 24. D 25. D




by accident 偶然

on account of 因为,由于,为了……的缘故

in addition to 另外,加之

in addition 除…之外(还)

in the air 流传中

on (the/an) average 按平均值,通常

on the basis of 根据,在…的基础上

at best 充其量,至多

for the better 好转,向好的方向发展

on board 在船(车或飞机)上

out of breath 喘不过气来

on business 因公,因事

in any case 无论如何,不管怎样

in case of 假如,如果发生;防备

in case 假使,以防(万一)

in no case 决不,无论如何不

by chance 偶然,碰巧

in charge (of) 负责,管理

(a)round the lock 日夜不停地

in common 共用的,共有的

in conclusion 最后,总之

on condition (that) 如果

in consequence of 由于…的缘故,因为

on the contrary 正相反

in contrast with/to 与…对比起来,与…形成对比

out of control 失去控制

under control 处于控制之下

at all cots 不惜任何代价,无论如何

at the cost of 以…为代价

in the course of 在…过程中,在…期间

of course 当然,自然

in danger 在危险中,垂危

out of danger 脱离危险

out of date 过时的,不用的

up to date 现代化的,切合目前情况的

in demand 非常需要的,受欢迎的

in debt 欠债,负债

in detail 详细他

in difficulties 处境困难

in the distance 在远处

off duty 下了班(的),不在值班(的)

on duty 在上班(的),在值班(的)

on earth 究竟,到底

at all events 无论如何,不管怎样

in any event 无论如何,不管怎样

in the event of 万一,倘若

for example 例如

in the face of 在…面前;不顾

in fact 其实,实际上

in favo(u)r of 赞同,支持

on fire 着火,起火

on foot 步行

in force 生效,有效;在实施中;大量的

in front of 在…面前,在…前面

in future 今后,从今以后

in the future 在将来

in general 一般说来,大体上

on (one’s) guard 警惕,提防;站岗,值班

in half 成两半

at hand 近在手边,在附近

by hand 用手,用体力

hand down 把…传下去

hand in hand 手拉手;密切关联地,同时并进地

in hand (工作等)在进行中;在控制中

on hand 在手边,在近处

on (the) one hand 一方面

on the other hand 另一方面

at heart 内心里,本质上

by heart 凭记性

at home 在家,在国内;舒适,无拘束;熟悉,精通

in hono(u)r of 为纪念,为了向…表示敬意

on/upon one’s hono(u)r 以名誉担保

in a hurry 匆忙,急于

for instance 例如;比如

at intervals 不时,每隔一段时间(或距离)

at (long) last 终于

at least 至少

at length 终于,最终;详细地

in (the) light of 鉴于,由于


have/gain access to 可以获得

take…into account 考虑到,顾及,体谅

take advantage of 占…的便宜,利用

pave the way (for) 铺平道路,为…作准备

pay attention to 注意

do/try one’s best 尽力,努力

get/have the best of 战胜

make the best of 充分利用

get/have the better of 战胜,在…中占上风

catch one’s breath 屏息;喘气,气喘;歇口气

take care 注意,当心

take care of 爱护,照料

take a chance 冒险,投机

take charge 开始管理,接管

keep…company 陪伴

take (a) delight in 以…为乐

make a difference 有影响,起(重要)作用

carry/bring/put into effect 使生效,实行,实现

come/go into effect 生效,实施

take effect 生效,起作用

catch sb’s eye 被某人看到,引起某人注意

keep an eye on 留神,照看,密切注意

make a face 做鬼脸

find fault with 抱怨,挑剔,找岔子

catch (on) fire 着火,开始燃烧

make fiends (with) 与(…)交朋友

be friends with 与…友好

make fun of 取笑,拿…开玩笑

keep sb’s head 保持镇静

in the world 究竟,到底

lose sb’s head 慌乱,仓皇失措

lose heart 丧失勇气,失去信心

get/catch/take hold of 抓住,得到 [page]

keep house 管理家务

throw/cast light on/upon 使人了解,阐明

bear/keep in mind 记住

have in mind 考虑到,想到

make up one’s mind 下定决心,打定主意

bring/put into operation 实施,使生效,使运行

come/go into operation 施行,实行,生效

keep pace (with) 与(…)齐步前进,与(…)并驾齐驱

play a part (in) 起作用,参与,扮演角色

take place 发生,进行,举行

take the place of 代替,取代

put into practice 实施,实行

make progress 进步,进展

give rise to 引起,导致为…的原因

make sense 讲得通,有意义,言之有理

catch sight of 发现,突然看见

(go) on the stage 当演员

take one’s time 不着急,不慌忙

keep track of 与…保持联系

lose track of 失去与…的联系,不能跟上…的进展

make use of 利用

put to use 使用

give way 让路;屈服,让步;倒塌,坍陷

make one’s way 前往,行进,去

make way 让路,腾出地方或位置


appeal to 呼吁,恳求

attempt at 企图,努力

attitude to/towards 态度,看法

a great/good deal of 大量,非常,极其

influence in 干涉,介入

interference with 妨碍,打扰

introduction to 介绍

a lot (of) 许多(的),大量(的)

lots of 大量,许多

fall in love (with sb) 爱上(某人)

reply to 回答,答复

trolley bus 电车

i.d. card 身份证

credit card 信用卡

no doubt 无疑地,很可能

next door 隔壁

out of doors 在户外

face to face 面对面地

a few 有些,几个

quite a few 不少,相当多

a little 一点,一些

little by little 逐渐地,一点点地

quite a little 相当多,不少

no matter 无论

the moment (that) 一…(就)

no more 不再

fair play 公平竞赛,公平对待

rest room 厕所,盥洗室

primary school 小学

side by side 肩并肩地,一起

heart and soul 全心全意

step by step 逐步地

ahead of time 提前

all the time 一直,始终

once upon a time 从前

once in a while 偶尔

no wonder 难怪,并不奇怪

word for word 逐字地

decline with thanks 婉言谢绝