首页 > 学历类考试

网友您好，请在下方输入框内输入要搜索的题目：

请输入或粘贴题目内容搜题

搜题

拍照、语音搜题，请扫码下载APP

题目内容（请给出正确答案）

[主观题]

Since the early 1980s, scientists have revealed some 40 human genes involved in cancer. Th

ese genes are essential for normal growth, but can be subverted to cause a tumor.

Dr. Jorge Yunis of the University of Minnesota Medical School in Minneapolis has found that 70 percent of oncogenes, or cancer-causing genes, are located near inherited weak points on chromosomes(染色体). Varying from individual to individual, vulnerable to chemical carcinogens(致癌剂), X rays and other cancer-inducing agents.

"If a chromosome snaps apart in the immediate vicinity of an oncogene," says Yunis, "normal genetic control mechanisms could break down and the stage would be set for the formation of cancer." Younis has shown that such a sequence occurs at the beginning of numerous leukemias (白血病), lymphomas(淋巴瘤) and some tumors of the lung, colon(结肠) and breast.

Yunis and other investigators have found that petroleum-based products--notably pesticides and insecticides-damage specific sites on at least two of the 23 pairs of human chromosomes that carry genetic information. Similarly, tobacco smoke tends to attack a part of another chromosome.

From paragraph 1, we know that some 40 genes involving in cancer are ______. ()

A．harmful to the human body

B．necessary to the human body

C．the elements that form. cancer

D．useless to the human body

答案

查看答案

发布时间：2022-04-17

更多“Since the early 1980s, scientists have revealed some 40 human genes involved in cancer. Th”相关的问题

第1题

He （lived) in Beijing （since) 1980 to 1997, but he （is now living) （in) Shanghai.A．livedB．

He (lived) in Beijing (since) 1980 to 1997, but he (is now living) (in) Shanghai.

A．lived

B．since

C．is now living

D．in

点击查看答案

第2题

It should be noted that the ____ between marriage and the birth of the first child has lengthened since the early seventies.

A.cycle

B.contrast

C.interval

D.circle

点击查看答案

第3题

We can conclude that accidents involving cars ______. A. happened most often in New Y

We can conclude that accidents involving cars ______.

A. happened most often in New York City

B. do not happen as often as they did in the early days of the auto

C. have killed many more people since Mr Bliss was killed

D. were always the driver's fault

点击查看答案

第4题

In the United States the most popular form. of folk dancing since the early days has been

square dancing. In early times, when men and women worked in groups to【21】a barn(谷仓) for harvest crops, they danced when the work was done. The music【22】from a violin for the most part. But if there was no one to play an instrument(乐器), clapping(击掌) was used to【23】the rhythm(节奏) by which to dance. The early settlers(移民) danced in a store, in a barn, or in a farm kitchen.

After some years【24】, square dancing became【25】popular in cities and towns, but it【26】popular in the country. Then it became popular in the cities once again. Today in【27】parts of the United States you will find some school, club, or other group that is square dancing for fun.

A square is formed by four couples(对，双) who stand【28】the center of the square. Each couple stands on one【29】of the square, the boy on the left and the girl on the right.

The "caller" is an important part of the【30】 since he tells the dancers which steps to do. If the dancers do not know the steps, he teaches them. It【31】 time to learn to be good caller, and good callers are always in demand.

Large or small groups of people can dance at one time. Sometimes 800 or 1,000 people may be dancing at the【32】 time. Or there may be only one square of【33】 people.

Costumes(服装) are worn by some who square dance. This【34】 the dancing more colorful to watch. The costumes vary(不同) from place to place. Women often wear full skirts of various colors with pretty blouse(罩衫). Men may have colored skirts and western trousers which they wear【35】 when square dancing.

(66)

A．make

B．set up

C．build

D．form

点击查看答案

第5题

On the 20th【D1】______ of the first official report on AIDS the head of the United Nations

AIDS programme warns the deadly disease may only be at its early stages in many parts of the world. Dr. Piot has said that the disease has already reached the【D2】______【D3】______ since first being【D4】______ in 1981. 58 million people world-wide have【D5】______ the HIV virus,which causes AIDS, while 22 million have 【D6】______related【D7】______. The UN estimates the worlds HIV-【D8】______ population at 36 million, including 25 million in Sub-Saharan Africa. International officials warned that the disease would have【D9】______ political, social and economic【D10】______ in many developing countries.

【D1】

点击查看答案

第6题

完成下列各题 In the United,States the most popular form. of folk dancing since the earl

y days has been square dancing．In early times，when men and women worked in groups to 21________ a barn(谷仓)for harvest crops，they danced when the work was done．The music 22________ from a violin for the most part．But if there was no one to play all instrument(乐器)，clapping(击掌)was used to 23________ the rhythm(节奏)by which to dance．The early settlers(移民＞danced in a store，in a barn，or in a farm kitchen． After some years 24 ________，square dancing became 25 ________ popular in cities and towns，but it 26________ popular in the country．Then it became popular in the cities once again·Today in 27 ________ Darts of the United States you will find some school，club，or other group that is square dancing for fl in． A square is formed by four．couples(对，双)who stand 28 ________the center of the square. Each couple stands on one 29________ 0f the square，the boy on the left and the girl on the right． The“caller”is an important part of the 30________ since he tells the dancers which steps to do． If the dancers do not know the steps，he teaches them．It 31________ time to learn to be a good caller，and good callers are always in demand． Large or small groups of people can dance at one time．Sometimes 800 or 1，000 people may be dancing at the 32 ________time．Or there may be only one square of 33________ people. Costumes(服装)are worn by some who square dance．This 34________ the dancing more colorful to watch．The costumes vary(不同)from place to place．Women often wear full skirts of various colors with pretty blouse(罩衫)．Men may have colored skirts and western trousers which they wear35________ when square dancing．

A.make

B.set up

C.build

D.form

点击查看答案

第7题

The computer is a wonderful machine. It is the most important invention since the type of

engine used in cars. Today it has the greatest effect on science, industry and business, but it is being used more in education and medicine. By the end of this century it will touch the lives of everyone, even people in distant villages. It is a revolutionary invention.

The oldest kind of computer is the abacus, used in China since the sixth century. In the seventeenth century an adding machine was invented, but the first large, modern computer was built in 1973. A few years later a computer could do 5,000 additions per second. Now the computations are so fast that they are measured in nanoseconds.

Today most computers are stored-program computers, that is, they have a memory. They are getting smaller and smaller, and computing faster and faster. Even in a large computer, the part that does the actual computing is about the size of the end of a finger.

Computers can do all kinds of work. When someone buys something in a department store, in formation about the sale goes into a computer. A scientist can talk to the computer about the rocks, and the computer answers the questions. A doctor can talk to the computer and explains what is wrong with a patient. If the doctor asks why, the computer goes through its stored information and ex plains exactly why.

When early humans began fanning, it was a revolutionary change in human life. It was hundreds of thousands of years later that people developed a writing system. In less than fifty years people have developed computers that can do most of the things humans can do. This could be a frightening development.

The oldest kind of computer, the abacus, has been used since ______.

A．600

B．700

C．800

D．500

点击查看答案

第8题

Across the United States, scientists are mounting what may become the most innovative agri

cultural research drive since the 1920's, when hybrid corn was developed. Surprisingly, the new genetic revolution is not taking place in America's fields. Instead, it is occurring in biology laboratories, for it involves the deliberate manipulation in test tubes of the genes of crop plants. This genetic engineering may prove the biggest boon to agriculture since plant breeding began.

The new concepts grew out of the bioengineering of bacteria for the production of such things as human hormones and vaccines for viral diseases. Plant cells, however, are far more complex than bacteria, and it will probably take many years for today's encouraging laboratory results to have a major impact on the farm. In fact the payoff may not come until the next century.

But although bio-technologists are still in the earliest phases of this new field of science, they are already actively exploring ways to redesign plants so they will use sunlight mere efficiently, resist viruses and other pests, grow in hot or dry areas, in saline soils or in the presence of pesticides, and perhaps even make their own fertilizer out of nitrogen in the air. In addition, scientists have had early success in making wholly new plants that are unavailable by conventional plant breeding-a potato-tomato combination, for example.

The new technology holds the promise of virtually limitless horizons in food production. Only imagination sets the limits: frost-resistant wheat, tropical potatoes, saltwater rice, a plant producing a combination of a pea and a carrot-all may be with us one day.

Vaccines for viral diseases are often produced from ______.

A．plant cells

B．human hormones

C．crop plants

D．bacteria

点击查看答案

第9题

•Read the following article about career development and the questions on the opposi

te page．

•For each question 15-20，mark one letter(A，B，C or D)on your Answer Sheet for the answer you choose．

How to get to the top

Marketing used to be the route to the chief executive's chair，but the world has changed．Now，says Monika Hamori．professor of human resources at Instituto de Empresa in Madrid，it is finance chiefs who are most likely to get the top job，though experience in opera-tions-running parts of the companyis also essential．CFO Magazine found in 2005 that onefifth of chief ex-ecutives in America were former chief financiaI officers，almost double the share of a decade earlier．The importance of quarterly financial reporting，and closer scrutiny since the imposition of the Sarbanesoxley corporategovernance act，have put CFOs in the limelightand given them the chance to shine．

Another factor in reaching the top is whether you stay with the company you joined as a youngster．Ms．Hamori's research looked at companies in the S&P 500 and the FTSEurofirst 300．She finds that‘lifers’get to the top in 22 years in America and 24 years in Europe：‘Hoppers’who jump between four or more companies，by contrast，take at least 26 years on average to become chief executives．Insiders get promotions that reflect their potential，because their bosses have enough information to be reasonably confident about their ability．When executives switch from one company to another，however，they tend to move less far up the hierarchy，the researchers found．

The time taken to reach the top is falling．The average time from first job to chief executive fell from 28 years in 1980 to 24 in 2001．Successful executives are spending less time than they used to in each intermediate joban average of four yearsand they fill five posts on the way up．down from six．One reason for this acceleration is that company hierarchies are flatter than they used to be．Another important shift is the advent of female chief executives． 1n 2001 women accounted for 11%of bosses at leading American companies．ac-cording to the Hamori/Cappelli survey；in the early 1980s there were none．

America is usually regarded as the home of raw capitalism．with youthful managers hopping from firm to firm and pushing their way to the top．But the HamorL/Cappelli study and another by Booz & Company，a consultancy，show that Europe is a more dynamic and harsher environ-menl than America or Japan for chief executives．For a start，European chief executives are younger，with an average age of 54．compared with over 56 in America．The Hamor/Cappelli study shows that 26%of American bos-ses were lifers，compared with only 18%in Europe．

The Europeans also have a harder time once they get to the top.Booz ＆ Company's annual survey of chiefexecutive succession shows that 17.6%of European bosses moved on last year．compared with 15%of Americans and 10%of Japanese．Chief executives．the survey found，last longer in America：the average tenure over the past decade was just over nine years．But in Europe the average tenure over the same period was less than seven years．

Moreover．a whopping 37%of changes at the top in Europe were more or less firings，according to Booz，compared with only 27%in America and 12%in Japan．Booz puts this down to the more recent tightening of corporate governance in Europe,Another Booz finding is common to both sides of the Atlantic：looking back over recent years，board disputes and power struggles lie behind a third of chiefexecutive firings．In short，shareholder activism is making its presence felt，putting pressure on bosses to perform．

What is true according to the first paragraph？

A．CFOs'hard work leads to their increasing chances of promotion．

B．CFOs usually have no experience in management．

C．Marketing directors no longer have the chance to get a top position．

D．Chief executives used to be promoted mainly from the marketing department．

点击查看答案

第10题

False teeth have been found in Italy in human heads that are over 2,500 years old

False teeth have been found in Italy in human heads that are over 2,500 years old. They were made of bone and set in gold. However，for hundreds of years afterwards，the apparent dental skill of those early people was lost. Without false teeth people looked old before their time，since so many lost their teeth at an early age.

Toward the end of the 17th century，rich people could buy false teeth made from ivory. The teeth were tied together with silk thread，but it was difficult to keep them in the mouth. That was why rich people would rather buy teeth from the poor who would often sell their teeth to buy food and clothing.

Early in the 18th century a French doctor used steel springs to hold teeth in place. However，it was difficult to close one‘s mouth! Late in the same century porcelain (瓷)teeth set in gold were often used to make false teeth.

Although the use of artificial teeth increased，human teeth continued to be used also. In the 19th century，teeth from soldiers killed in battle were made into artificial teeth. For example，teeth from the dead in the American Civil War were sent to England.

By the middle of the 19th century，an American doctor，Claudius Ash，invented a better kind of porcelain tooth made of a special kind of hard rubber.

26.When did people with the earliest false teeth live according to the passage？

[A] At the end of the 17th century.

[B] In the early 18th century.

[C] In the middle of the 19th century.

[D] Over 2,500 years ago.

27.Which material would wealthy people use to make artificial teeth in 1693？

[A] Porcelain.

[B] Hard rubber.

[C] Ivory.

[D] Bone.

28.Who first used steel springs to tie false teeth together according to the passage？

[A] An Italian doctor.

[B] A French doctor.

[C] An American doctor.

[D] An English doctor.

29.We can learn from the passage that ___________.

[A] one looked older than his real age with artificial teeth

[B] we are using the same method as ancient people in making false teeth

[C] poor people would often sell their teeth to get money in the 17th century

[D] human teeth were no longer used in making false teeth after the 18th century

30.The passage is mainly about ___________.

[A] the discovery of false teeth

[B] the material of false teeth

[C] the use of false teeth

[D] the history of false teeth Passage Three

点击查看答案

账号：尚未登录

登录没有账号？去注册

购买搜题卡

下载APP

关注公众号

TOP