精英家教网 > 高中英语 > 题目详情
     Caffeine not only gives us a daily jump start, but new research suggests it also can strengthen long-term memory.
According to the US Food and Drug Administration, nearly 90 percent of people worldwide consume about 200 milligrams of caffeine each day. That' s equivalent to about one strong cup of coffee a day. Writing in " Nature Neuroscience" , Johns Hopkins University researchers say their findings show that caffeine strengthens certain memories for up t0 24 hours after being taken in.
" We've always known that  caffeine has  cognitive-enhancing effects (促智效果) , but its ,particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans, "  said senior author of the paper Michael Yassa. " We re- port for the first time a specific effect of caffeine on reducing forgetting over 24 hours. "      Conducting a double-blind trial, the researchers worked with a test group of people who didn't regularly consume caffeinated products. Five minutes after studying a series of images, the  test subjects were given either a placebo(无效对照剂)  or a 200-milligram caffeine tablet.
To check the caffeine levels of their test subjects, the research team took saliva samples (唾液样品)  from them before they took their tablets and again one, three and 24 hours after- wards.
Both groups of test participants ( those who took the placebo and those who took the caffeine tablet) were tested the following day to see if they could recognize the images they' d seen the previous day.
The test included showing the test subjects another series of images that included some new images , those that were shown the previous day, as well as other images that were similar, but not the same as those they had viewed earlier.
The researchers found that more members of the group who were given the caffeine tablets were able to correctly identify some of the new images as " similar" to previously viewed images rather than incorrectly identifying them as the same.
"We also know that caffeine is associated with health and longevity(长寿) and may havesome protective  effects  from  cognitive  decline  like  Alzheimer' s  disease (阿尔茨海默症). " said Yassa.
小题1:The purpose of the new research is
A.to survey how much caffeine people consume a day
B.to write the paper " Nature Neuroscience"
C.to prove caffeine has cognitive-enhancing effects
D.to examine caffeine ' s memory-strengthening effects in detail
小题2: During the research ,the researchers did the following things EXCEPT
A.giving the test subjects placebos or caffeine tablets
B.checking the caffeine levels of the test subjects
C.encouraging the test subjects to drink more coffee
D.showing the test subjects series of images
小题3: How did the test subjects show the caffeine ' s memory-strengthening effects?
A.By recognizing images they ' d seen the previous day.
B.By taking the caffeine tablets instead of placebos.
C.By identifying the new images as the same.
D.By telling the differences between new images.
小题4: What will the next part of the text possibly talk about?
A.Ways to achieve health and longevity.
B.The effects caffeine has on health.
C.The treatment for Alzheimer' s disease.
D.The harmful effects of cognitive decline.

小题1:D
小题2:C
小题3:A
小题4:B
本文主要叙述了一个实验来证明咖啡因对人的长期记忆的积极影响。
小题1:D
【试题解析】推理题。根据文章第三段Conducting a double-blind trial, the researchers worked with a test group of people who didn't regularly consume caffeinated products. Five minutes after studying a series of images, the  test subjects were given either a placebo(无效对照剂)  or a 200-milligram caffeine tablet. 可知这次试验只是为了检验咖啡因对于长期记忆的影响。故D正确。
小题2:C
【试题解析】细节题。根据文章第二段the  test subjects were given either a placebo(无效对照剂)  or a 200-milligram caffeine tablet可知A是试验内容。根据文章第4段To check the caffeine levels of their test subjects, the research team took saliva samples (唾液样品)  from them before they took their tablets and again one, three and 24 hours after- wards.可知B是试验的内容。根据Both groups of test participants ( those who took the placebo and those who took the caffeine tablet) were tested the following day to see if they could recognize the images they' d seen the previous day.可知D项是试验内容。只有C项在文章里没有提及。
小题3:A
【试题解析】推理题。根据文章倒数第二段The researchers found that more members of the group who were given the caffeine tablets were able to correctly identify some of the new images as " similar" to previously viewed images rather than incorrectly identifying them as the same.可知研究人员主要是通过让参加试验的人来辨认之前给他们看见的照片来检验咖啡因对人的长期记忆的影响的。故A正确。
小题4:B
【试题解析】推理题。根据文章最后一段第一行"We also know that caffeine is associated with health and longevity(长寿)可知咖啡因对于人的健康也有影响,那么在下面一段一个展开讨论这个话题。故B正确。
【长难句解析】
The researchers found that more members of the group who were given the caffeine tablets were able to correctly identify some of the new images as " similar" to previously viewed images rather than incorrectly identifying them as the same.
【翻译】研究人员分析被给含有咖啡因胶囊的那一组里更多的成员能够准确辨认与先前所给的相似形状的形象而不是错误地认为她们是一样地。
【分析】本句中动词found后面接的是宾语从句,宾语从句中含有定语从句who were given the caffeine tablets;介词短语rather than后面接动名词短语identifying them as the same。
练习册系列答案
相关习题

科目:高中英语 来源:不详 题型:阅读理解

     What exactly is a Dream Career? I am sure it means different things to different people. You could presently be unsure about what your final job would be. If you have any doubts about what your dream career is, you may know which careers you definitely would not like to do. For example, if you have an interest in art, and do not like math, you most certainly would not be an engineer .If you love art. and have no artist talent ,maybe you would like to be around art instead, as an art curator (馆长)
A career related to your passion, bobby, or special interest, is the path to follow in finding your dream job. Try thinking about what things you like to do in your spare time. Many are attracted toward turning what they love to do in their off work hours into a full time job. For example, if you like to put together model cars, maybe you would like opening your own hobby shop, or work for someone who owns one.
Once you find what you arc interested in doing, you can then match this to a career which will be similar to what you are passionate about. What you consider a dream career has to centre around what kind of person you actually are. This is called your Career Personality. What type of person do you consider yourself to be? People are naturally attracted to those things which reflect  who they are as unique individuals. For example, if you are slightly on the shy side, maybe you would like a job where you work on your own. relatively unsupervised ,behind a computer. If you are outgoing, maybe you would like to work with others, and be the supervisor.
All it may take to find our dream career is to know ourselves a little better, trust in our own judgment, and be realistic about what we can attain occupationally: This is how I found what I am doing now.
小题1:What is the main purpose of the passage?
A.To explain what a dream career really is.
B.To offer tips on finding a dream career.
C.To tell us what Career Personality means.
D.To give examples of different personalities.
小题2: Which of the following about Career Personality is TRUE?
A.One should choose a dream career by his/her personality.
B.Choosing a dream career depends on a person's ability.
C.One should choose a dream career according to the reality.
D.One should try different types of careers by his/her ability.
小题3: Which of the following is what we need to find a dream career?
a. Realizing our ability.
b. Believing in ourselves.
c. Having a better understanding of ourselves.
d. Considering the background of our family.
A.a, c, dB.a, b, cC.b, c, dD.a, c, d
小题4:From the second paragraph we learn your dream career has something to do with the
following EXCEPT ______.
A.your hobbyB.your special interest
C.your part-time jobD.your passion
小题5:55. It can be inferred from the passage that
A.a dream job is one that most people are fond of
B.people all want to turn their part-time jobs into full-time ones
C.finding our dream career should follow different suggestions
D.the author's present dream job is chosen by his personality

查看答案和解析>>

科目:高中英语 来源:不详 题型:阅读理解

Facebook (脸谱网) friends cannot replace the real thing, say psychologists(心理学家).
People are happier and laugh 50% more when they talk face to face with friends or via webcam (web camera) than when they use social networking sites, a study has found.
Dr. Roberts, a famous lecture at the University of Chester, said such websites don't appear to help make true friendships. Based on two questionnaires(调查表), he found there was no link between Facebook use and people with larger groups of friends.
Dr. Roberts, whose work will be presented at the British Psychological Society conference in Harrogate, said, "The bottom lime conclusion is that our relationships are not dependent on the quantity of communication. They depend on quality, and even Skype(一种网络即时语音沟通工具) is better at increasing the quality of our communication than time on Facebook." Even talking on the phone or texting does not make people feel as good as sharing a smile, the research says. The studies suggest quality, not quantity, of communication is the most important for keeping friends for life.
People find the most satisfying relationships come from a small number of close friends, with an outer "ring" of 10 significant others. With these people, it doesn't matter what type of social media you use for communication. But people who want to "contact the world at large" using Facebook can be disappointed because they spread themselves too thinly, claim researchers.
In a third study, Dr. Roberts asked people to communicate with friends face to face or via Skype and keep a 14-day diary. This was compared with communicating via phone, text messages or social networking sites. People communicating face to face on Skype were 50% more likely to laugh, and they rated themselves as significantly happier.
小题1: Dr. Roberts's finding that there was no connection between Facebook use and people with many friends was         .
A.based on questionnairesB.based on conversations
C.through instant messagesD.through social media
小题2: What is the idea of the fourth paragraph?
A.Most people contact each other online.
B.Keeping a friend for life is not easy.
C.The quality of communication is important.
D.Skype is better at understanding us than Facebook.
小题3: What does the underlined sentence in the fifth paragraph probably suggest?
A.They are too excited to express themselves.
B.They limit their social circle to a small range.
C.They spread their information at a low speed.
D.They lack information to introduce themselves.
小题4: What is Dr. Roberts's attitude towards the use of Facebook?
A.Positive.B.Casual.C.Responsible.D.Unsupportive.

查看答案和解析>>

科目:高中英语 来源:不详 题型:阅读理解

Across the globe, single parent homes are on the rise. In the US, the 2000 census (人口普查) showed 24.8 million, or nearly 24 percent of the nation’s 105.5 million households, were traditional two-parent homes. By comparison, 9.8 million households, or 9 percent of all US households were headed by an adult raising a child alone. The 1990 census showed 26 percent of homes were led by a married mother and father, and 8 percent of homes were led by a single parent.
Similar increases occurred in other countries. In the UK, lone-parent homes increased from 3.3 percent in 1990 to 5.5 percent in 1999. Single parent households in Australia rose from 5.8 percent in 1990 to 7.6 percent in 1999. Belgium saw the increase from 1.8 percent to 2.7 percent during the same period of time. These countries tend to have greater acceptance of the single parent because there are fewer nearby family members to disapprove, Riche, a Census Bureau director, said.
Just as in the US, those changes raised new questions about how involved govenment should be in helping single parent families. Some research suggests children raised in two-parent families are better off than those who depend on one.
“The position of one-parent families in any country is very much a gender (性别) issue-women’s opportunities, especially working-class women on low income,” said Sue Cohen, coordinator (协调员) of the Single Action Parents Network in England.
5.Not considering the exact number of the single-parent families, which country saw the fastest rise rate in 1999, compared with 1990?
A.UK.          B.Australia.               C.America.               D.Belgium.
6.What is the cause of the rise of single parent families across the globe?
A.The nearby family members have a favourable opinion.
B.A lone parent is well off enough to support his /her children.
C.A lot of problems have arisen in two-parent families.
D.We cannot get enough proving information from the text.
7.Which of the following is TRUE about the increase of single parent families according to the passage?
A.It will somewhat limit the growing population of younger generation.
B.Governments should take actions about the social problems brought about by it.
C.Single parent families are not looked down upon in any country mentioned here.
D.Generally speaking, the single parents needn’t worry since they are highly paid.
8.Which of the following diagrams correctly shows the rise of single parent families in the US from
1990 to 2000?

查看答案和解析>>

科目:高中英语 来源:不详 题型:阅读理解

Last summer, two nineteenth-century cottages were rescued from remote farm fields in Montana, to be moved to an Art Deco building in San Francisco. The houses were made of wood. These cottages once housed early settlers as they worked the dry Montana soil; now they hold Twitter engineers.
The cottages could be an example of the industry’ s odd love affair with “low technology,” a concept associated with the natural world, and with old-school craftsmanship (手艺) that exists long before the Internet era. Low technology is not virtual (虚拟的) —so, to take advantage of it, Internet companies have had to get creative. The rescued wood cottages, fitted by hand in the late eighteen-hundreds, are an obvious example, but Twitter’s designs lie on the extreme end. Other companies are using a broader interpretation (阐释) of low technology that focuses on nature.
Amazon is building three glass spheres filled with trees, so that employees can “work and socialize in a more natural, park-like setting.” At Google’s office, an entire floor is carpeted in glass. Facebook’s second Menlo Park campus will have a rooftop park with a walking trail.
Olle Lundberg, the founder of Lundberg Design, has worked with many tech companies over the years. “We have lost the connection to the maker in our lives, and our tech engineers are the ones who feel impoverished (贫乏的) , because they’re surrounded by the digital world,” he says. “They’re looking for a way to regain their individual identity, and we’ve found that introducing real crafts is one way to do that.”
This craft based theory is rooted in history, William Morris, the English artist and writer, turned back to pre-industrial arts in the eighteen-sixties, just after the Industrial Revolution. The Arts and Crafts movement defined itself against machines. “Without creative human occupation, people became disconnected from life,” Morris said.
Research has shown that natural environments can restore(恢复) our mental capacities. In Japan, patients are encouraged to “forest-bathe,” taking walks through woods to lower their blood pressure.
These health benefits apply to the workplace as well. Rachel Kaplvin, a professor of environmental psychology, has spent years researching the restorative effects of natural environment. Her research found that workers with access to nature at the office—even simple views of trees and flowers—felt their jobs were less stressful and more satisfying. If low-tech offices can potentially nourish the brains and improve the mental health of employees then, fine, bring on the cottages.
小题1:The writer mentions the two nineteenth-century cottages to show that ________.
A.Twitter is having a hard time
B.old cottages are in need of protection
C.early settlers once suffered from a dry climate in Montana
D.Internet companies have rediscovered the benefits of low technology
小题2:Low technology is regarded as something that _______.
A.is related to natureB.is out of date today
C.consumes too much energyD.exists in the virtual world
小题3:The main idea of Paragraph 5 is that human beings ________.
A.have destroyed many pre-industrial arts
B.have a tradition of valuing arts and crafts
C.can become intelligent by learning history
D.can regain their individual identity by using machines
小题4:The writer’s attitude to “low technology” can best be described as ________.
A.positiveB.defensiveC.cautiousD.doubtful
小题5:What might be the best title for the passage?
A.Past Glories, Future Dreams
B.The Virtual World, the Real Challenge
C.High-tech Companies, Low-tech Offices
D.The More Craftsmanship, the Less Creativity

查看答案和解析>>

科目:高中英语 来源:不详 题型:阅读理解

Research shows that much of  our predisposition (倾向) towards determination, sociability and self­control and sense of purpose is in our genes. In  fact, our DNA plays a bigger role in influencing these traits (characteristics) than our upbringing (儿童期的教养) and the company we keep.  Taken together, these aspects of personality can make the difference between success and failure, say the Edinburgh University researchers.
They questioned more than 800 pairs of twins about  their attitudes to life to tease apart the influences of nature  and nurture. Comparing identical twins, who share all their  DNA and their upbringing, with non­identical twins, who  have a shared background but are no more genetically alike  than other brothers and sisters, is a technique often used  by researchers to quantify the influence of genetics.
The results, published in the Journal of Personality,  showed that genes play a much bigger role than lifestyle,  with self­control particularly etched (铭刻) into our DNA.
Our genes also largely determine how determined and persistent we are. This is important in terms of success, as someone who refuses to give up is more likely to achieve their dreams than someone_who_throws_in_the_towel_at_the_first_hiccough.
Researcher Professor Timothy Bates said, “Ever since the ancient Greeks, people have debated the nature of a good life and the nature of a virtuous life. Why do some people seem to manage their lives, have good relationships and cooperate to achieve their goals while others do not? Previously, the role of family and the environment around the home often controlled people's ideas about what affected psychological well­being. However, this work emphasizes a much more powerful influence from genetics.”
However, those who haven't been dealt a helpful hand of genes shouldn't be too depressed. The professor says a sense of purpose is the key and advises those who are eager for success to focus their thoughts on making a difference.
小题1:What does the result of the research indicate?
A.Our DNA is the only factor to decide our traits.
B.Our DNA plays a decisive role in achieving success.
C.Education plays little part in the formation of our character.
D.Society has little effect on us in our personality.
小题2:The underlined part in Paragraph 4 refers to someone   who ________.
A.is born successful
B.determines to make a difference
C.makes great effort
D.admits defeat easily
小题3:Timothy Bates mentions the ancient Greeks in order to   indicate that ________.
A.some people can live a good life because they can manage their lives
B.people haven't made it clear yet what is the key personality trait to be a success
C.in ancient Greece the role of family and the environment was ignored
D.the relationship between personality and success has always been people's concern
小题4:According to the passage, the key personality trait is ________.
A.determination      B.kindness
C.politenessD.sociability
小题5:What is the best title for the passage?
A.How do people work hard?
B.Why can some people succeed?
C.DNA determines success or failure.
D.Several factors determine personality.

查看答案和解析>>

科目:高中英语 来源:不详 题型:单选题

Think of the last time a song really moved you, or meant something to you.Listening to and playing music affects marry different sections of the brain, affecting us physically as well. Why are we as humans so connected to music?
Making music is something that we are born with. There's a reason we refer to music as the “universal language”;there has been no known human culture without music. Dancing and music came before agriculture, and possibly even before language.The fact that whale music and human music have so much in common suggests that music may exist before humans and that we may be latecomers to the musical scene rather than being the inventors of music.
We begin life being affected by music; babies first begin to respond to music even before their birth. Whether or not it's true, everyone has heard that playing classical music; for your baby supposedly helps him or her become smarter. A study done in the United Kingdom concluded that children were able to recognize and even preferred music that they had heard lip to three months before birth. Although it made no difference whether it was rock music or country music, the babies who were exposed to faster songs showed a stronger preference for that song than those who had heard something slower. Researchers have also found that the playing of soft background music or a mother's soft singing actually helps premature (早产的)babies. Those who were subjected to the music tended to gain weight faster and were able to leave hospitals earlier than those who weren't. However, the study in the UK uncovers no links between babies listening to music and increased intelligence or brain development.
Another experiment at the University of California at Irvine compared the puzzle-solving abilities of 3-year-olds who were given piano lessons with the ability of others who sang, used computers, or did nothing. The children studying piano were better at the puzzles. Also, high school students with a musical background seem to do better on their SATs. Whether it's natural intelligence that helps the children excel in both music and math, or the music that helps develop other areas, you can't deny the benefits of a musical background.    
On the other hand, it's possible that some music and lyrics(歌词)could be hard for children and teenagers.The lyrics of today's popular music are stated more and more clearly. A study oil mass media and teenagers showed that a group of 14- to 16-year-olds in 10 different southeastern cities listened to music an average of 40 hours per week. Obviously, the music they are listening to plays a large part in their lives,and especially influences self-identity. So any bad influences in the music will have a very direct effect on the teenagers.     Several other experiments mentioned in the American Academy of Pediatrics' policy statement on the "Effect of Music Lyrics and Music Videos on Children and Youth" supported this idea. One study from Sweden found that children who developed a preference to rock music were more likely to be influenced by their peers than by their parents. Others showed links between a predilection for heavy metal and detrimental behaviors, including taking drugs, self-killing risk, and other risk-taking habits. The American Academy of Pediatrics (AAP) doesn't support the idea of censorship(检查制度), but strongly encourages parents to monitor what their children are listening to.
小题1:Music is regarded as the “universal language” because ______.
A.music is important for human beings’ mental and physical health
B.music is played by people from all over the world
C.music is of great benefits to human language
D.music is present throughout the development of human culture
小题2:Which of the following proves a musical background benefits children a lot?
A.An experiment at the University of California.
B.A study done in the United kingdom.
C.A study on mass media and teenagers.
D.A study from Sweden.
小题3:According to Paragraph 3, what affects babies’ preference for songs?
A.The lyricsB.The tone C.The styleD.The speed
小题4:The author mentioned several other experiments in the AAP’s policy statement to prove________.
A.parents should monitor what their children are listening to
B.music can have harmful effects on teenagers
C.teenagers are more likely to be affected by their friends
D.children shouldn’t be exposed to too much music
小题5:What will the author probably discuss in the paragraph that follows?
A.More bad effects of music on teenagers’ daily habits.
B.Some experiments about music and teenagers.
C.Tips for parents on monitoring the music their children prefer.
D.Benefits of listening to a variety of music.

查看答案和解析>>

科目:高中英语 来源:不详 题型:阅读理解

The sound of a mosquito can mean trouble in many parts of the world. The bite of the mosquito can be deadly. The insects carry serious diseases like malaria. It is estimated that almost 630,000 people died from malaria and malaria-related causes in 2012, and most of these cases were in African countries.
In the United States, a group of California scientists is working to develop a more effective and less costly substance(物质)to protect people from mosquitoes. The researchers are investigating the sense of smell in mosquitoes. They found the insects use the same receptor(感受器)for identifying carbon dioxide in human breath as they do for the smell of our skin. Anandasankar Ray, who is leading the investigation, says scientists tested more than a million chemical compounds(化合物)until they found a substance called Ethyl pyruvate. He says Ethyl pyruvate makes the mosquitoes' receptor inactive. ”When we apply Ethyl pyruvate to a human arm and offer it to hungry mosquitoes in a cage, very few of the mosquitoes are attracted to the human arm because only a few of them are able to smell it out,” said Ray.
Genevieve Tauxe, a member of the research team, says it was not easy to find the neurons (神经元)of nose cells that recognise both the smell of human breath and skin. "With the device used to examine mosquitoes, we are able to insert a very small electrode(电极)into the part of the mosquitoes' nose, where its smelling neurons are and where the smell is happening," said Tauxe.
Anandasankar Ray says a product based on Ethyl pyruvate may cost less to produce than DEFT,the most effective chemical treatment now in use. He says DEFT is too costly for most people who live in areas affected by malaria.
“Perhaps by finding smells that can attack other target receptors, we will be able to improve upon DEFT and finally have the next generation of insect behavior control products," said Ray.
小题1:The best title for the passage is most probably _______________________________.
A.Scientists Find New Substance to Fight Mosquitoes
B.A New Generation of DEET Has Been Developed to Kill Mosquitoes
C.Malaria一a Serious Disease Causing 630,000 Deaths
D.Ethyl Pyruvate一an Insect Behavior Control Product
小题2:According to the passage, Ethyl Pyruvate can_______________________________.
A.kill the mosquitoes' smelling neurons
B.cause the mosquitoes to lose their sense of smell
C.result in the inactiveness of the mosquitoes' receptor
D.make the mosquitoes uninterested in human breath and skin smell
小题3:Through the passage, the writer aims to_______________________________.
A.inform readers of the new development in fighting mosquitoes
B.praise the achievements made in the battle against malaria
C.introduce a cheaper product in fighting mosquitoes
D.tell the differences between Ethyl Pyruvate and DEET
小题4:This passage most probably appears in_______________________________.
A.the column of newspaper ads
B.the health column of a magazine
C.a textbook of medical schools
D.a collection of doctors' essays

查看答案和解析>>

科目:高中英语 来源:不详 题型:阅读理解

Running like the wind, roaring (咆哮) like thunder, tigers have long been feared and respected as a king of the animal world. But last week a report said that there are no more than 30 wild tigers left in south China.
This was the conclusion of a team of scientists from China's State Forestry Administration and the World Nature Fund.
The South China tiger, also known as the Chinese tiger, is native to southern China. In the 1950's, there were over 4000 tigers found in mountain forests in the country. But due to the destruction of their natural habitat and uncontrolled hunting, it has been pushed on to the list of the world's top ten most endangered species.
Sixty­six of the big cats can be found in the cages of a dozen zoos around China. But they are nothing like their wild cousins. They have lost their natural skills such as hunting and killing. If they were set free they could not look after themselves.
“Breeding has damaged the quality of the species”, said Pei Enle, deputy director of the Shanghai Zoo.
To reintroduce the species into the wild, the country started a programme to send five to ten young tigers to South Africa. Four of them have already arrived. Progress has been made as two elder tigers have recovered some of their instincts(本能) and can hunt wild animals by themselves at the African base.
“South Africans are very experienced in reintroducing big animals to the wild. The country has very good natural conditions for the tigers to learn in”, said Lu Jun, office director of the National Wildlife Research and Development Center.“We tried in Fujian Province, but it was not successful as there was not a complete eco­chain(生物链) and there was a lack of space.”
The tigers should return to China in 2007 when the reservations in Fujian are ready.
小题1:What is the main reason for the South China tiger becoming one of the world's top ten most endangered species?
A.Because it has lost its natural instincts.
B.Because there is not a complete eco­chain.
C.Because there is no space for it.
D.Because uncontrolled hunting has destroyed its natural living conditions.
小题2:How is the programme of sending several tigers to South Africa getting on?
A.Its effect still remains to be seen.
B.Two tigers can already compete with their wild cousins.
C.Some of the tigers are already on the road to recovering their natural skills.
D.The tigers should be able to recover their instincts completely by 2007.
小题3:By saying “but they are nothing like their wild cousins”,the writer means that________.
A.they are no longer feared by other wild animals
B.they don't know how to hunt or kill
C.a complete change has resulted in the species because of breeding
D.to reintroduce them into the wild has become an urgent task
小题4:What is the purpose of sending young tigers to South Africa?
A.To help the tigers recover their ability to live in the wild.
B.To provide them with a better environment.
C.To get the tigers to go on a tour.
D.To find a complete eco­chain for them.
小题5:Which one is NOT the reason for South Africa being chosen as the training place?
A.Because the tigers can hunt wild animals by themselves at the African base.
B.Because South Africans are skilled at dealing with the tigers.
C.Because there is a complete eco­chain and enough space there.
D.Because the country has good natural conditions for the tigers to learn in.

查看答案和解析>>

同步练习册答案