Mice and rats have long been used in medical research because of their biological similarities to humans. Recently scientists at the University of Richmond in Virginia have trained rats to drive small vehicles.
The research team built tiny cars out of plastic and other materials, which had an opening at one end to which electrical wires were attached. By touching one of three different wires, the rat could control the car in different directions-left, center and right. Sweet treats were placed inside the containers in an attempt to get the rats to drive the vehicle for the food. After several months' training, the animals could drive to get to the treats.
Kelly Lambert, who has long been interested in the way the brain changes to react to different experiences and difficulties, led the experiment. She told the French news agency AFP the research suggested rat brains might be more complex and flexible than once thought. The driving activity seemed to help the rats relax and the rats kept in what was called “enriched environments” performed far better than those in labs.
The researchers examined levels of two hormones (荷尔蒙) in the rats — one that causes stress and the other that counters it. All the rats that took part in the training had higher levels of the hormone that reduces stress. The research suggests the increased relaxation levels could be linked to the enjoyment of successfully completing a new skill. The team also found the rats that drove themselves showed higher levels of the stress-fighting hormone than those that simply rode in small cars controlled by humans.
Lambert's team is planning to further the research to learn more about how the rats learned to drive. This research may open new areas of non-drug treatments for people suffering from mental health conditions.
1.Why have scientists chosen rats for the research?
A.They can build tiny vehicles on their own.
B.They are biologically similar to human beings.
C.They are clever enough to be trained to drive cars.
D.They can be used as non-drug treatments for humans.
2.What does the underlined word "counters" in paragraph 4 mean?
A.removes. B.substitutes.
C.resists. D.transforms.
3.What can we learn about the experiment?
A.The brains of rats might be more complex and flexible than those of human beings.
B.The increased relaxation levels led to the rats' enjoyment of learning a new skill.
C.All the rats involved in the training had higher levels of the hormone causing stress.
D.The rats in cars controlled by humans had lower levels of the stress-fighting hormone.
4.In which section of a newspaper may this text appear?
A.Science. B.Sports.
C.Education. D.Entertainment.
高三英语阅读理解简单题
Mice and rats have long been used in medical research because of their biological similarities to humans. Recently scientists at the University of Richmond in Virginia have trained rats to drive small vehicles.
The research team built tiny cars out of plastic and other materials, which had an opening at one end to which electrical wires were attached. By touching one of three different wires, the rat could control the car in different directions-left, center and right. Sweet treats were placed inside the containers in an attempt to get the rats to drive the vehicle for the food. After several months' training, the animals could drive to get to the treats.
Kelly Lambert, who has long been interested in the way the brain changes to react to different experiences and difficulties, led the experiment. She told the French news agency AFP the research suggested rat brains might be more complex and flexible than once thought. The driving activity seemed to help the rats relax and the rats kept in what was called “enriched environments” performed far better than those in labs.
The researchers examined levels of two hormones (荷尔蒙) in the rats — one that causes stress and the other that counters it. All the rats that took part in the training had higher levels of the hormone that reduces stress. The research suggests the increased relaxation levels could be linked to the enjoyment of successfully completing a new skill. The team also found the rats that drove themselves showed higher levels of the stress-fighting hormone than those that simply rode in small cars controlled by humans.
Lambert's team is planning to further the research to learn more about how the rats learned to drive. This research may open new areas of non-drug treatments for people suffering from mental health conditions.
1.Why have scientists chosen rats for the research?
A.They can build tiny vehicles on their own.
B.They are biologically similar to human beings.
C.They are clever enough to be trained to drive cars.
D.They can be used as non-drug treatments for humans.
2.What does the underlined word "counters" in paragraph 4 mean?
A.removes. B.substitutes.
C.resists. D.transforms.
3.What can we learn about the experiment?
A.The brains of rats might be more complex and flexible than those of human beings.
B.The increased relaxation levels led to the rats' enjoyment of learning a new skill.
C.All the rats involved in the training had higher levels of the hormone causing stress.
D.The rats in cars controlled by humans had lower levels of the stress-fighting hormone.
4.In which section of a newspaper may this text appear?
A.Science. B.Sports.
C.Education. D.Entertainment.
高三英语阅读理解简单题查看答案及解析
Mice and rats have long been used in medical research because of their biological similarities to humans. Now, scientists have trained rats to drive small vehicles created for them. One of the main findings of the experiment was that the driving activity seemed to help the rats relax.
Researchers at the University of Richmond in Virginia led the experiment. The team built tiny cars out of plastic and other materials. The vehicles had an opening at one end where electrical wires were attached. By touching one of three different wires, the rat could control the direction of the vehicle.
Researchers trained 17 rats over several months to drive around the experiment containers. The animals proved that they could be trained to drive forward as well as in other directions to get to the sweet treats placed inside the containers.
The researchers examined levels of two hormones (荷尔蒙) in the rats—one that causes stress and another that reduces it. All rats that took part in the training had higher levels of the hormone that reduces stress. The research suggests the increased relaxation levels could be linked to the enjoyment of successfully completing a new skill. The team also found that the rats that drove themselves showed higher levels of the stress-fighting hormone than those that simply rode in small cars controlled by humans.
Lambert said the most exciting result of the experiment for her was about the possible effect on humans. The research may open new areas of non-drug treatments for people suffering from mental health conditions.
“There’s no cure for schizophrenia or depression and we need to catch up,” she said. “And I think we need to look at different animal models and different types of tasks and really respect that behavior can change our neurochemistry (神经化学). ”
Speaking to the British-based magazine New Scientist, Lambert said her team is planning to continue experiments to learn more about how the rats learned to drive. The new research will also examine why some activities appear to reduce stress, and which areas of the brain are involved in the process.
1.What did the experiment find?
A.Rats are able to drive vehicles. B.Rats feel relaxed when driving.
C.Rats can be used in medical research. D.Rats are biologically similar to humans.
2.The finding of the hormone examination in the rats suggests that ___________.
A.one hormone causes stress and another reduces it B.acquiring a new skill brings about joy
C.levels of hormone are controlled by stress D.relaxation contributes to enjoyment
3.The research is significant because ___________.
A.it may lead to a way to treat human mental problems
B.it will affect the way that humans drive their cars
C.it may help people train animals better.
D.it can surely change neurochemistry
4.What Lambert’s team will do next is find out ___________.
A.which parts of the rats’ brain control their emotions
B.why rats have the ability of fighting stress
C.when activities affect the levels of stress
D.why certain activities reduce stress
高三英语阅读理解困难题查看答案及解析
Baths and bathing have long been considered of medical importance to man. In Greece there are the ruins of a bathtub and water system built over 3, 000 years ago. The Romans had warm public baths. In some as many as 3, 000 persons could bathe at the same time.
Treating disease by bathing has been popular for centuries. Modern medical bathing or hydrotherapy, first became popular in Europe and by the late 1700’s has also become popular in the United States.
For many years frequent bathing was believed to be bad for one’s health. Ordinary bathing just to keep clean was avoided and perfume（香水）was often used to cover up body smells!
By the 1770’s doctors began to say that soap and water were good for health. They believed that it was good for people to be cleaned. Slowly people began to bathe more frequently. During the Victorian Age of the late 19th century, taking a bath on Saturday night became common.
In the United States ordinary bathing was slow to become popular. During the 18th and early 19th centuries, many Americans were known as “The Great Unwashed!” In one American city, for example, a person could only take a bath every thirty days! That was a law!
Frequency of bathing today is partly a matter of habit. People know that bathing for cleanness is important to health. Doctors know that dirty bodies increase the chance of diseases. Consequently, in the United States, people generally bathe often. Some people bathe once a day at least. They consider a daily bath essential to good health.
1.In Greece ________ .
A. there were some public baths large enough to hold 3, 000 persons.
B. people used to treat disease by bathing
C. people began to bathe thousands of years ago
D. people didn’t like frequent bathing
2.The Americans used to be known as “The Great Unwashed” because ________.
A. the modem medical bathing first became popular in the U. S.
B. they didn’t bath frequently
C. the Americans were very clean.
D. soap was first produced in the U. S.
3.In the 18th century doctors believed that being clean was _______ .
A. unimportant B. good for health
C. harmful D. popular
4.During the Victorian Age,________.
A. the Americans ever took a bath every thirty days
B. frequent bathing was avoided
C. people used perfume to cover up body smells after bathing
D. the British people generally took a bath once a week.
高三英语阅读理解中等难度题查看答案及解析
Baths have long been considered of medical importance to man. In Greece there are the ruins of a water system for baths built over 3,000 years ago. The Romans had warm public baths. In some baths, as many 3,000 persons could bathe at the same time.
Treating disease by taking bathing has been popular for centuries. Modern medical bathing first became popular in Europe and by the late 1700’s has also become popular in the United States.
For many years frequent bathing was believed to be bad for one’s health. Ordinary bathing just to keep clean was avoided, and perfume was often used to cover up body smells!
By the 1700’s doctors began to say that soap and water were good for health. They believed that it was good for people to be clean. Slowly, people began to bathe more frequently. During the Victorian Age of the late 19th century, taking a bath on Saturday night became comon.
In the United States ordinary bathing was slow to become popular. During the 18th and early 19th centuries, many Americans were known as “The Great Unwashed!” In one American city , for example, a person was only allowed to take a bath every thirty days! That was a law!
Frequency of bathing today is partly a matter of habit. People know that bathing for cleanliness is important to health, Doctors know that dirty bodies increase the chance of diseases. As a result, in the United States, people generally bathe often. Some people bathe once a day at least. They consider a daily bath essential to good health.
1.A water system for baths was built by _______ over 3,000 years ago.
A. the Romans B. the Greeks
C. the Americans D. the Europeans
2.Dirty bodies can ______ .
A. ruin one’s business B. cause disease
C. drive customers away D. cause good health
3.In the 18th century doctors believed that being clean was .
A. unimportant B. good for health C. harmful D. important
4.The underlined word perfume probably means .
A. a sweet smelling substance B. good health
C. a strange smelling substance D. large wealth
5.Which of the following gives the main idea of the passage?
A. Everybody in America takes a daily bath.
B. We should often take baths
C. Taking baths has become popular in the world.
D. Bathing has become easier and cheaper.
高三英语阅读理解中等难度题查看答案及解析
Protests (抗议) at the use of animals in research have taken on a new and fearful character in Britain with the attempted murder of two British scientists by the terrorist (恐怖分子的) technique of the pre-planted car–bomb .
The research community (社团) will rightly be alarmed at these developments which have two aims :to draw public attention and to frighten people working in research with animals . The scientists insist that everything should be done to identify those responsible for the crimes and to put them on trial . The Defense Research Society has taken the practical step of offering a reward of £10，000 for information leading to those responsible , but past experience is not encouraging . People are unlikely to be attracted by such offers . The professional police will similarly be challenged by the problem of finding a needle in a haystack .
That is why the intellectual (知识分子) community in Britain and elsewhere must act more strongly in its own defense . There are several steps that can be taken , of which the chief one is to demand of all the organizations that exist with the declared aims of defending the interests of animals that they should declare clearly where they stand on violence towards people . And it will not be enough for the chairman and chairwoman of these organizations to make placatory (安抚的) statements on behalf of all their members . These people should also promise that it will be a test of continuing membership in their organizations that members and would-be members should declare that they will take no part in acts of violence against human beings .
67．The words “these developments” (Linel , Para .2 ) most probably refer to ________ .
A．the use of animals in research
B．the acts of violence against scientists
C．the techniques of planting bombs in cars
D．setting up of new animal protection organizations
68．Which of the following is true according to the passage ?
A．The police gave up their efforts to find the criminals .
B．The terrorists escaped with the help of their organization .
C．The attempted murder caused great anxiety among British scientists .
D．People supported the animal protectors in spite of their extremist acts .
69．The author’s purpose in writing this article is to demand that animal-protecting organizations ________ .
A．give up the use of violence
B．declare their aims clearly
C．continue the dialogue with the scientific community
D．help to fid those responsible for the attempted murder
70．In the author’s opinion ,________ .
A．animal-protecting organizations should be declared illegal
B．the scientists should take effective measures to protect themselves
C．since people can lie , the problem about eh rights of scientists can’t be solved
D．animal-protecting organizations should help the police to fight against the acts of violence
against scientists
高三英语阅读理解简单题查看答案及解析
One in four children and young people could have problematic smart-phone use, according to research that also suggests such behaviour is associated with poorer mental health.
The amount of time children and teens spend using their devices has become an issue of growing concern, but experts say there is still little evidence as to whether spending time on screens is harmful in itself.
The experts behind the latest study said they wanted to look beyond the time young people were spending on smart-phones and instead explore the type of relationship they had with smart-phones.
The results suggest more than 23% of young people have an abnormal relationship with their smart-phones, and that this appears to be associated with poorer mental health-although the research cannot say whether phone use is driving such problems.
“It seems like only a minority of teenagers and young people from various different countries are self-reporting a pattern of behaviour that we recognise from other addictions,” said Dr Nicola Kalk of King’s College London, co-author of the study. “The quality of the evidence is poor, but it is enough to warrant (保证) further investigation.”
Writing in the journal BMC Psychiatry, the team reported how they looked at data from 41 studies involving a total of almost 42,000 participants across Europe, Asia and America, mainly in their teens or early 20s.
These studies used questionnaires to probe the prevalence (普遍) of problematic smart-phone use-behaviours such as being anxious when the device is not available or neglecting other activities to spend time on the smart-phone.
Taken together, the team said on average these studies suggested as many as one in four children and young people had problematic smart-phone use.
Among the studies that probed mental health, the results suggested people with problematic smart-phone use were also more likely to have depression-for which the odds (可能性) were more than three times worse-anxiety, feelings of stress and poor sleep as well as poorer educational attainment.
While the team said it was too soon to call problematic smart-phone usage an addiction, they noted that it appeared to be linked to similar patterns of behaviour and emotion.
Kalk said further studies were needed to explore if these behaviours were hard to break, or cause harm-other key features of an addiction.
The authors argued that the availability and pervasiveness of smart-phones in everyday life meant problematic use of the devices posed a different and much bigger public health problem than substances of abuse or internet gaming.
Kalk said the team were now looking at whether smart-phones were just delivering addictive content, or whether there was something inherently addictive about using such devices.
Dr Amy Orben, an expert in screen time at the University of Cambridge, raised concerns, noting that the definition of problematic internet use varied considerably across studies, and the measures used were questioned.
She said studies finding little signs of problematic internet use might have been overlooked, while the research could not say whether problematic smart-phone use caused poorer mental health.
Prof Russell Viner, President of Royal College of Paediatrics and Child Health, said that parents were navigating unchartered water when it came to technology.
“One of the most critical things for parents to consider is whether screen time is having a harmful impact on other activities like school, relationships or other interests. This study suggests that this is the case for a significant minority of children and young people,” he said.
Viner said in these cases parents should calmly install age-appropriate boundaries on smart-phone use, and ask questions about whether their children were experiencing other problems.
“While screen time is a new problem, part of the solution is tried and tested-open and regular conversations based on respect and trust,” he said.
1.Experts conducted the research to ______.
A.address the concern about adolescent behavior
B.prove spending time on screens is harmful in itself
C.calculate the time young people spent on smart-phones
D.explore young people’s relationship type with smart-phones
2.We can learn from the research that ______.
A.it involved a vast majority of participants across the globe
B.the participants were asked to report their online activities
C.researchers compared different behaviors of the participants
D.problematic smart-phone use is linked to poorer mental health
3.Which of the following might Kalk probably agree?
A.It is hard to break problematic smart-phone use.
B.Internet gaming is problematic smart-phone use.
C.Problematic smart-phone use is an addiction.
D.The research still has some limitations.
4.What’s Dr Amy Orben’s attitude towards the research findings?
A.Supportive. B.Negative.
C.Sceptical. D.Unconcerned.
5.What does the underlined part in Paragraph 16 mean?
A.Screen time is a new challenge to parents.
B.Technology is posing a threat to parents.
C.Parents are lost in the sea of technology.
D.Parents use technology to chart water.
6.According to Viner, what should parents do to solve the problem?
A.Keep track of the screen time of children.
B.Strictly prohibit children from using devices.
C.Have a sincere communication with children.
D.Evaluate the impact of screen time on children.
高三英语阅读理解困难题查看答案及解析
In a major medical breakthrough, Tel Aviv University researchers have “printed” the world's first 3D vascularized (有血管的）engineered heart using a patient’s own cells and biological materials. Their findings were published on April IS in a study in Advanced Science.
“This is the first time anyone anywhere has successfully engineered and printed an entire heart,” says Prof. Tal Dvir of Department of Materials Science and Engineering, who led the research for the study. “This heart is made from human cells and patient-specific biological materials. In our process, these materials serve as the bioinks, something made of sugars and proteins that can be used for 3D printing of complex tissue models，” Prof, Dvir says. “People managed to 3D print the structure of a heart in the past, but not with cells or with blood vessels (血管).Our results demonstrate the potential of our approach for engineering personalized tissue and organ replacement in the future.”
According to Prof. Dvir，the use of “ native ” patient-specific materials is important to successfully engineering tissues and organs.
The researchers are now planning on culturing the printed hearts in the lab and “ teaching them to behave” like hearts, Prof. Dvir says. They then plan to transplant the 3D-printed heart in animal models.
“We need to develop the printed heart further，” he concludes. “The cells need to form a pumping ability ； they can currently contract (收缩），but we need them to work together. Our hope is that we will succeed and prove our method’s efficacy (功效)and usefulness. “Maybe, in ten years, there will be organ printers in the finest hospitals around the world，and these procedures will be conducted routinely. ”
1.What does Prof. Dvir think of an early 3D-printed heart?
A.It was highly practical. B.It was too expensive.
C.It was personalized. D.It was too simple.
2.What do we know about the latest 3D-printed heart?
A.It can be cultured in the lab.
B.It can match a patient perfectly.
C.It has been transplanted in animals.
D.It has been widely used in hospitals,
3.What is Prof, Dvir's attitude to the development of the printed heart?
A.Ambiguous. B.Positive.
C.Disapproving. D.Cautious.
4.What is the author's purpose in writing the text?
A.To explain the basic principle of 3D technology.
B.To introduce a breakthrough of medical research.
C.To doubt the medical value of a new invention.
D.To prove the effectiveness of the new technology.
高三英语阅读理解困难题查看答案及解析
Bahamas’ 4 Best Budget Beachfront Hotels
Hundreds of islands and beaches in Bahamas have long been attractions for travelers. Here are 4 unique beach destinations.
Pigeon Cay Beach Club
Pigeon Cay Beach Club is located on the largely undeveloped Cat Island, where it’s possible to wander the coastline for miles without spotting a soul. TVs, AC, and Wi-Fi are all off-duty, leaving guests to explore the island by bike and boat. Meals can be served at the beach bar, on the beach, or in the cottages, which all have full kitchens and furnished outdoor spaces.
Compass Point Beach Resort
Compass Point Beach Resort may be Bahamas’ most interesting property. The resort was opened in 1995 by a music producer. Its appearance is as noticeable as its history. It’s composed of 18 rainbow-colored small wooden houses. All rooms have surround-sound music systems, open-air kitchens and dining spaces.
Stella Maris Resort Club
If you’re looking for a casual, cheerful, and cheap life, the beachfront Stella Maris Resort Club more than fits the bill. The large, family-owned complex is a bargain for its competitive rates and accommodations that suit larger parties. One of the highlights of the resort is its range of activities, many of which are free, including day trips, boating, nature walks and caving.
St Francis Resort
If you want to go off the Internet, St Francis Resort is as remote as you can get. The resort is only accessible by boat and has little human development: no cars, no roads, and only about two dozen residents. But it’s not all peace and quiet: the restaurant draws plenty of boaters and day-travelers and the hotel hosts activities like poker nights and weekly barbecues.
1.What characteristic do Pigeon Cay Beach Club and St Francis Resort share?
A.They are undeveloped and poorly-furnished. B.They offer various night outdoor activities.
C.They are rich in unique local culture. D.They have no access to the Internet.
2.Where would you prefer to go if you are a music fan?
A.Pigeon Cay Beach Club. B.Stella Maris Resort Club.
C.Compass Point Beach Resort. D.St Francis Resort.
3.Which of the following can best describe life in Stella Maris Resort Club?
A.Luxury and comfortable. B.Relaxing and inexpensive.
C.Exciting and competitive. D.Informal and peaceful.
高三英语阅读理解中等难度题查看答案及解析
In the 1960s, medical researchers Thomas Holmes and Richard Rahe developed a checklist of stressful events. They appreciated the tricky point that any major change can be stressful. Bad events like "serious illness of a family member" were high on the list, but so were some helpful life-changing events like marriage.
When you take the Holmes-Rahe test you must remember that the score does not show how you deal with stress － it only shows how much you have to deal with. And we now know that the way you deal with these events dramatically (戏剧性的) affects your chances of staying healthy. By the early 1970s, hundreds of similar studies had followed Holmes and Rahe. And millions of Americans who work and live under stress worried over the reports. Somehow the research got boiled down to a memorable message. Women's magazines ran titles like "Stress causes illness".
If you want to stay physically and mentally healthy the articles said avoid stressful events. But such simplistic advice is impossible to follow. Even if stressful events are dangerous , many — like the death of a loved one — are impossible to avoid. Moreover, any warning to avoid all stressful events is a prescription (处方) for staying away from chances as well as trouble. Since any change can be stressful, a person who wanted to be completely free of stress would never marry, have a child, take a new job or move. The idea that all stress makes you sick also takes no notice of a lot of what we know about people. It supposes we' re all vulnerable and not active in the face of the difficult situation. But what about human ability and creativity? Many come through periods of stress with more physical and mental strength than they had before. We also know that a long time without change or challenge can lead to boredom and physical and mental pressure.
1.The result of Holmes-Rahe’s medical research tells us _________________.
A. the way you deal with major events may cause stress
B. what should be done to avoid stress
C. what kind of event would cause stress
D. how to deal with sudden changes in life
2.The studies on stress in the early 1970s led to ___________________.
A. popular avoidance of stressful jobs
B. great fear over the mental disorder
C. a careful research into stress-related illnesses
D. widespread worry about its harmful effects
3.The score of the Holmes-Rahe test shows ________________.
A. how you can deal with life-changing events
B. how helpful events can change your life
C. how stressful a major event can be
D. how much pressure you are under
4.Why is “such simplistic advice” (Line 1, Paragraph 3) impossible to follow?
A. No one can stay on the same job for long.
B. No prescription is effective in reducing stress.
C. People have to get married someday.
D. You could be missing chances as well.
5.According to the passage people who have experienced ups and downs may become _______.
A. nervous when faced with difficulties B. physically and mentally tired
C. more able to deal with difficulties D. cold toward what happens to them
高三英语阅读理解中等难度题查看答案及解析
In the 1960s, medical researchers Thomas Holmes and Richard Rahe developed a checklist of stressful events. They appreciated the tricky point that any major change can be stressful. Negative events like “serious illness of a family member” were high on the list, but so were some positive life-changing events, like marriage. When you take the Holmes-Rahe test you must remember that the score does not reflect how you deal with stress — it only shows how much you have to deal with. And we now know that the way you handle these events dramatically affects your chances of staying healthy.
By the early 1970s, hundreds of similar studies had followed Holmes and Rahe. And millions of Americans who work and live under stress worried over the reports. Somehow, the research got boiled down to a memorable message. Women’s magazines ran headlines like “Stress causes illness!” If you want to stay physically and mentally healthy, the articles said, avoid stressful events.
But such simplistic advice is impossible to follow. Even if stressful events are dangerous, many — like the death of a loved one — are impossible to avoid. Moreover, any warning to avoid all stressful events is a prescription (处方) for staying away from opportunities as well as trouble. Since any change can be stressful, a person who wanted to be completely free of stress would never marry, have a child, take a new job or move.
The concept that all stress makes you sick also ignores a lot of what we know about people. It assumes we’re all vulnerable (脆弱的) and passive in face of tough conditions. But what about human initiative (主动性) and creativity? Many come through periods of stress with more physical and mental strength than they had before. We also know that a long time without change or challenge can lead to boredom, and physical and mental strain.
1.The result of Holmes-Rahe’s medical research tells us ________.
A. how to handle major events causes stress
B. what should be carried out to avoid stress
C. how to deal with sudden changes in life
D. what kind of event would cause stress
2.The studies on stress in the early 1970s led to ________.
A. great fear over the mental disorder
B. popular avoidance of stressful jobs
C. widespread worry about its harmful effects
D. a careful research into stress-related illnesses
3.Which of the following expressions is the closest in meaning to the underlined phrase in paragraph 2?
A. was summarized as B. was quarrelled about
C. was made clear D. was brought to an end
4.Why is “such simplistic advice” (Line 1, Paragraph 3) impossible to follow?
A. People have to get married someday.
B. You could be missing chances as well.
C. No prescription is effective in reducing stress.
D. No one can stay on the same vocation for long.
5.According to the passage, people who have experienced ups and downs may become _____.
A. more flexible to deal with difficulties
B. nervous in face of various difficulties
C. physically and mentally exhausted
D. insensitive toward what happens to them
高三英语阅读理解中等难度题查看答案及解析