2011年理工类职称英语教材新增文章

第三十八篇
Longer Lives for Wild Elephants
Most people think of zoos as safe places for animals，where struggles such as difficulty finding food and avoiding predators don’t exist. Without such problems，animals in zoos should live to a ripe old age1.
But that may not be true for2 the largest land animals on Earth. Scientists have known that elephants in zoos often suffer from poor health. They develop diseases，joint problems and behavior changes. Sometimes, they even become infertile，or unable to have babies.
To learn more about how captivity affects elephants，a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care，documenting factors such as birth dates, illnesses, weight and death. These records made it possible for me researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe. The scientists compared the life spans of the zoo-born elephants with the life spans of thousands of female wild elephants in Africa and Asian elephants that work in logging camps3，over approximately the same time period.
The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years-more than three times as long. Female Asian elephants followed a similar pattern. In zoos，they lived 18.9 years，while those in the logging camps lived41.7 years.
Scientists don't yet know why wild elephants seem to fare so much better than their zoo-raised counterparts. Georgia Mason，a biologist at the University of Guelph in Canada who led the study，thinks stress and obesity may be to blame4.Zoo elephants don't get the same kind of exercise they would in the wild，and most are very fat. Elephant social lives are also much different in zoos than in the wild，where they live in large herds and family groups.
Another finding from the study showed that Asian elephants born in zoos were more likely to die early than Asian elephants captured in the wild and brought to zoos. Mason suggests stress in the mothers in zoos might cause them to have babies that are less likely to survive.
The study raises some questions about acquiring more elephants to keep in zoos. While some threatened and endangered species living in zoos reproduce successfully and maintain healthy populations，that doesn't appear to be the case with elephants. "Currently，zoos are net consumers of elephants，not net producers," Mason says.
词汇：
predator n.食肉动物 captivity/ n.监禁;束缚
ripe adj.成熟的 fare v.过活，生活
infertile adj.不生育的 obesity n.过度肥胖;肥胖症
注释：
1.1ive to a ripe old age：这是一种固定用法，意思是live to an age that is considered to be very old(长寿，高寿)。
2.be true for：或者be true of：对……适用。短文中第二段第一句：But that may not be true for
the largest land animals on Earth.这里，作为主语的that指的是第一段所陈述的内容。这个句子要传达的意思是：动物园对其他动物来说是一个安栖之地，而对大象来说却不然。
3.logging camps：伐木场。Logging作为名词，意思是：伐木业。
4.stress and obesity may be to blame：压力和肥胖是问题的根源。be to blame：该受责备，应承担责任。
练习：
1.According to the first two paragraphs，unlike other zoo animals，zoo elephants
A.have difficulty eating food.
B.1ive to a ripe old age.
C.are not afraid of predators.
D.develop health problems.
2.Which of the following about the international scientists' research on the life spans of elephants is NOT true?(See paragraph 3)?
A.They compared zoo elephants with wild elephants.
B.They kept detailed records of all the elephants in their care.
C.They analyzed the records of the elephants kept in zoos.
D.The zoo-born elephants they studied are kept in European zoos.
3.What do the scientist find in their research?
A.Female elephants live longer than male elephants.
B.Female zoo elephants live longer than their wild counterparts.
C.Female zoo elephants die much earlier than their wild counterparts.
D.Elephants in zoos and those in the wild enjoy the same long life spans.
4.What are the possible causes of stress and obesity Zoo-raised elephants generally suffer from?
A.They do not like living in herds.
B.They do not get enough exercise.
C.They do not live with their families.
D.Both B and C.
5.Which of the following does the author suggest in the last paragraph 7?
A.It may not be a wise policy to keep elephants in the zoo.
B. Elephants are no longer an endangered species.
C.Zoo-born elephants should be looked after more carefully.
D.Zoos should keep more animals except elephants.
答案与题解：
1.D 短文的第一段告诉我们，人们通常认为动物园内的动物没有猎食的困难，也不受其他猎食动物的威胁，所以一般寿命较长。但第一段并没有提及大象。第二段则说，动物园内的大象却不然，它们面临很多健康问题。所以，除了D以外，其他选项均不符合这两段内容。
2.B 第三段告诉我们，动物园，而不是这些研究人员，保存了所有园内动物的详细相关信息。所以应该选择B。其他三个选项均能在该段中找到相关内容。
3.C 短文的第四段提供了答案。该段告诉我们，野生的雌性大象的平均寿命是动物园里的雌性大象平均寿命的3倍还多。
4.D 短文的第五段提供了答案。该段第三句的意思是：动物园里的大象不像野生大象那样活动，因此非常肥胖。他们也不像野生大象那样过着群居的生活，即live in herds and family groups。
5.A 短文通篇陈述了大象在动物园内的生存问题，最后一段是全文的总结。该段第一句指出，对动物园大象的研究向人们提出了一个问题：是否应该将更多的大象关进动 物园。该段还重复了第一、第二段的观点：其他动物在动物园能够很好地繁衍生息，而大象却不能。所以，A是正确选择。B、C、D均没有在文中被提及 第四十五篇
Some People Do Not Taste Salt Like Others
Low-salt foods may be harder for some people to like than others，according to a study by a Penn State College of Agricultural Sciences1 food scientist. The research indicates that genetic factors influence some of the difference in the levels of salt we like to eat.
Those conclusions are important because recent，well-publicized efforts to reduce the salt content in food2 have left many people struggling to accept fare that simply does not taste as good to them as it does to others3，pointed out John Hayes，assistant professor of food science，who was lead investigator4 on the study.
Diets high in salt can increase the risk of high blood pressure and stroke. That is why public health experts and food companies are working together on ways to help consumers lower salt intake through foods that are enjoyable to eat. This study increases understanding of salt preference and consumption.
The research involved 87 carefully screened participants who sampled salty foods such as soup and chips，on multiple occasions，spread out over weeks5.Test subjects were 45 men and 42 women，reportedly healthy，ranging in age from 20 to 40 years. The sample was composed of individuals who were not actively modifying their dietary intake and did not smoke cigarettes. They rated the intensity of taste on a commonly used scientific scale，ranging from barely detectable to strongest sensation of any kind.
“Most of US like the taste of salt. However，some individuals eat more salt，both because they like the taste of saltiness more，and also because it is needed to block other unpleasant tastes in food. "said Hayes." Supertasters，people who experience tastes more intensely，consume more salt than nontasters do. Snack foods have saltiness as their primary flavor，and at least for these foods，more is better，so the supertasters seem to like them more.”
However，supertasters also need higher levels of salt to block unpleasant bitter tastes in foods such as cheese，Hayes noted. "For example，cheese is a wonderful blend of dairy flavors from fermented milk，but also bitter tastes from ripening that are blocked by salt," he said. "A supertaster finds low-salt cheese unpleasant because the bitterness is too pronouncedo6."
Hayes cited research done more than 75 years ago by a chemist named Fox and a geneticist named Blakeslee，showing that individuals differ in their ability to taste certain chemicals. As a result，Hayes explained，we know that a wide range in taste acuity exists，and this variation is as normal as variations in eye and hair color.
“Some people，called supertasters，describe bitter compounds as being extremely bitter，while others. called nontasters，find these same bitter compounds to be tasteless or only weakly bitter，"he said." Response to bitter compounds is one of many ways to identify biological difterences in food preference because supertasting7 is not limited to bitterness. (476)
词汇：
publicize v.引起公众对…的注意;(用广告)宣传 ferment v.(使)发酵
geneticist n.遗传学家
dietary adj.饮食的;规定食物的 acuity n.敏锐;尖锐
注释：
1.Penn State College of Agricultural Sciences：即Penn State University-College of Agricultural Sciences宾州州立大学农学院。Penn是Pennsylvania的缩写，是美国宾夕法尼亚州州名。宾州州立大学建于1855年，在全国共有24 个分校。在句中，Penn State College of Agricultural Sciences用作定语，修饰food scientist。
2.well-publicized efforts to reduce the salt content in food：大力宣传减少食物含盐量的做法
3.1eft many people struggling to accept fare that simply does not taste as good to them as it does to others：使得许多人努力去接受适合其他人而不适合他们口味的食物。fare相当于food。
4.1ead investigator：研发项目负责人
5.…carefully screened participants who sampled salty foods as soup and chips，on multiple occasion，spread out over weeks：……经过仔细筛选的实验参与者，他们在几周内的不同时间里品尝了汤和薯条等含盐食物。
6.too pronounced：此处pronounced为形容词，意为very noticeable，conspicuous(明显的，显著的)。
7.supertasting：超重味感
练习：
1.In paragraph 2，John Hayes points out that
A.it is good to health to eat food without salt.
B.many people reject low-salt food completely.
C.many people accept low-salt tasteless food reluctantly
D.food with reduced salt tastes better.
2.The fourth paragraph describes briefly
A.how to select subjects and what to do in the research.
B.how to identify supertasters and nontasters.
C.why to limit the number of subjects to 87 persons.
D.why to select more male subjects than female ones.
3.The article argues that supertasters
A.1ike the taste of saltiness to block sweet tastes in food. .
B.1ike snack foods as saltiness is their primary flavor.
C.consume less salt because they don t like intensive tastes.
D.1ike to share salty cheese with nontasters.
4.Which of the following applies to supertasters in terms of bitter taste?
A.They like bitterness in foods as well as saltiness.
B.They like high-salt cheese as it has intense bitter taste.
C.They prefer high-salt cheese，which tastes less bitter.
D.They prefer high-salt cheese as it is good to health.
5.What message do the last two paragraphs carry?
A.Taste acuity is genetically determined.
B.Taste acuity is developed over time after birth.
C.Taste acuity is related to one’s eye and hair color.
D.Taste acuity is still a mysterious subject in science.
答案与题解：
1.C 根据短文的第二段内容，很多人因为食物中的含盐量降低，所以必须做出很大努力(struggling)去适应，而低盐食物对于他们来说，口味很不好 (fare that simply does not taste…good to them)。选项C有accept reluctantly(勉强接受)表达了这层意思，所以是正确的选择。A、B、D三个选项均是错误的。
2.A第四段介绍了科学家是如何设计这项研究的，它包含了研究对象的人数、性别、人选条件、咸度味感分级表等。选项A概括了这方面的内容，所以是答案。而选项B、C、D所述内容均不符合该段的意思。
3.B短文的第五段提供了答案。supertaster在这里的意思是：口味重的人，在本文中，nontaster是其反义词，即，口味清谈的人。该段 告诉我们，口味重的人消耗更多的盐;因为快餐食品的主要味道就是咸味，而且咸度越高，口味越好，所以口味重的人对快餐较为偏爱。选项B表达了上述内容，所 以是答案。
4.C短文第六段提供了答案。该段告诉我们，奶酪发酵会产生苦味，supertasters不喜欢苦味，而高含盐量可以盖住奶酪里的苦味，这是他们偏爱高盐奶酪的原因。所以，只有C是正确选择。
5.A 文章第七段中，Hayes引用了75年前一位遗传学专家的实验。从这项实验中，Hayes得出的结论是，Taste acuity(味觉敏度)上的差异与他们头发和眼睛的颜色上的差异是同一类
现象，也就是说，都是与生俱来的。第八段又说，这是一种biological difference(生物差异)，所以A是答案。B说味觉敏度是后天形成的，显然与作者的结论相左。C说味觉敏度的差异与头发和眼睛的颜色上的差异有 关，显然是错误的。D的内容在最后两段都没有提到，所以不会是答案