选择知识点

An infectious disease is a disease that is caused by the invasion of a host by pathogens（病原体）whose activities harm the host's tissues and can be spread to other individuals.
Microorganisms（微生物）capable of causing disease are called pathogens. A true pathogen is an infectious agent that causes disease in any possible host. The terms "infection" and "disease" are quite different. In order to cause disease, pathogens must be able to enter the host body, stick to specific host cells, invade and multiply and do damage to host tissues.
Pathogens may be spread through either direct or indirect contact. Direct contact occurs when an individual is infected by contact with the infection source. It also includes taking in the infectious droplets released by sneezing or coughing. Indirect contact occurs when a pathogen can survive the environment outside its host for a long period of time. So lifeless objects that are polluted by direct contact with the infection source may be the indirect contact for easily infected group.
Public health measures typically involve killing the pathogen from its source or from its route of spread. Those measures include ensuring a safe water supply,effectively treating waste water,and initiating animal control and vaccination（疫苗）programs,etc. Personally,the first line of defense is to keep pathogen at bay by following good personal hygiene（卫生）habits. Prevent infection before it begins and avoid spreading it to others with some easy measures, such as washing hands, getting vaccinated and so on.
Man never stops fighting against all kinds of infectious diseases. But in the past two decades at least a dozen "new" disease have been identified,and traditional diseases that appeared to be "on their way out" are re-emerging. Globally,infectious diseases remain the leading cause of death. Clearly,the battle has not been won. Nevertheless, it is increasingly difficult for most of us to deny the claims of science. We are continually presented with great amounts of relevant scientific and medical knowledge, which encourages us to take more responsibility for our own health.



What does paragraph 2 focus on？ ______

A. Origin of true pathogens.
B. Nature of infectious diseases.
C. Strategies for avoiding tissue damage.
D. Differences between infection and disease.

What is likely to cause disease spread through indirect contact？ ______

A. Getting bitten by an infected dog.
B. Playing toys a sick child played with.
C. Breathing in tiny drops from sneezing
D. Shaking hands with an infected person.

Which of the following can best explain the underlined phrase "at bay" in paragraph 4？ ______

A. At risk.
B. Off course.
C. Under control.
D. Within reach.

What does the last paragraph imply？ ______

A. Man is at a loss about infectious diseases.
B. Traditional infectious diseases are dying out.
C. Science counts in defeating infectious diseases.
D. The battle against infectious diseases is in vain.

You'll need to take a deep breath before hearing this news. A surprising 93% of kids around the world live in environments with air pollution levels that are damaging their health, according to a new report by WHO.
Air pollution is to blame for the deaths of 543，000 kids under 5 in 2016， with more than one in four deaths of children under five years old being related to environmental issues. Exposure （暴露）to air pollution can damage the health of kids in a variety of ways, either causing or being associated with everything from low birth weight to childhood obesity and so on.
"The large toll of disease and death revealed （揭示）by these new data should result in an urgent call to action for the global community especially for those in the health department"， WHO stated. Strong action to reduce exposure to air pollution offers an opportunity to protect the health of children. The report stressed that health experts should communicate with families, communities and policy-makers about the serious risks of air pollution exposure. "Although more researches into how air pollution affects children's health will continue to be valuable, there is already evidence to justify strong, swift action to prevent the damage it clearly produces," WHO added.
Disease caused by dirty air is more common in low-and-middle income countries, especially those in Africa, South-East Asia, and Western Pacific regions.Poor countries in these areas have the highest levels of exposure to household air pollution due to the use of polluting fuels and technologies for basic needs like cooking, heating and lighting.
Advised solutions include cleaner transport, cleaner cooking and heating fuels and technologies energy-efficient housing and urban planning, safer industrial technologies and better waste management.



What is the second paragraph mainly about？ ______

A. The serious result of air pollution.
B. The deaths caused by air pollution.
C. The illnesses children are suffering.
D. The way to fight air pollution.

What does the underlined word "toll" in Paragraph 3 mean？ ______

A. Threat.
B. Number.
C. Fact.
D. Report.

What are health experts asked to do？ ______

A. Do more researches.
B. Find ways to fight air pollution.
C. Develop cleaner fuels and technologies.
D. Make people aware of the serious risks.

What can we learn from the text？ ______

A. Researches of this kind have stopped.
B. Air pollution caused 543，000 kids' death in 2016.
C. Air pollution is more serious in low-and-middle-income countries.
D. Nothing can be done to stop air pollution at present.

Japanese researchers are genetically changing mosquitoes so that they become carriers of a vaccine （疫苗）that could vaccinate millions for free. The researchers have already genetically changed a mosquito species so that its saliva （唾液） contains a protein that acts as a vaccine against leishmaniasis （利什曼病），a deadly disease that leads to terrible skin problems. The team confirmed that mice bitten by the genetically engineered mosquito developed an antibody to the disease, meaning they had built up immunity （免疫力）.
"You would be vaccinated without even noticing. You wouldn't need any drug and you wouldn't need to show up at a fixed place for mass vaccinations," said Shigeto Yoshida, the associate professor who has led the research. "Repeated bites would only strengthen the immunity."
"Similarly the mosquitoes could be used to help treat malaria （疟疾）， perhaps a decade from now," said the malaria expert.
Nearly one million people die each year from malaria-most of them are children-mainly in Africa and Asia, according to the World Health Organization. Now a problem is that no effective vaccine exists. "There is a treatment that works, but it is beyond the reach of people who need to worry about food for tomorrow," Yoshida said.
However, Yoshida expects that the genetically-engineered mosquito will finally help wipe out the deadly disease in the developing world. "Technically speaking, I believe it's a matter of 10 years or so,but it's not clear whether society would accept it," he said.
Another problem is that the genetically-engineered mosquito may still pick up and spread the infected blood of a person who has already caught malaria. Yoshida's team is hoping it can solve this problem by developing a mosquito species that kills the malaria virus inside its own body.



How have scientists turned mosquitoes into carriers of a vaccine？ ______

A. By changing their genes.
B. By killing the virus in their bodies.
C. By letting them bite mice.
D. By injecting vaccines into their bodies.

Which of the following is NOT an advantage of using mosquitoes as vaccine carriers？ ______

A. It's free of charge.
B. It's convenient.
C. It's more effective.
D. It's unnoticeable.

What can we infer from the last two paragraphs？ ______

A. People welcome the idea of using mosquitoes to treat malaria.
B. Mosquitoes carrying vaccines may still spread malaria.
C. It is not long before people will use mosquitoes to get rid of malaria.
D. A mosquito can kill the malaria virus inside its own body.

The main purpose of the passage is to ______ .

A. introduce a possible solution to malaria
B. encourage people to use mosquitoes to fight against diseases
C. show that Japan has very advanced technology
D. call on people to help people suffering from malaria in Africa and Asia

In a study published in Frontiers in Psychology,European neuroscientists（神经系统科学家）determines that our fears of snakes and spiders are inborn,even babies become alarmed at the sight of them.How did they figure it out？Well,they "scared" some babies for science!
Though not everyone is frightened of snakes and spiders,studies have shown more than a third of the child population and adult population have a strong dislike of them,and they're the most reported specific fear sources.Even though poisonous spiders and snakes aren't a huge problem for most of us now,they're still "ancestral threats" our primate ancestors had to deal with for millions of years.
Scientists have already shown these fears are deep-seated to most people,but they are usually in adults or adolescents,so it is possible they've learned such fears from their environments.To really prove whether or not human brains are automatically wired to dislike snakes and spiders,the experiments had to test people with almost no environmental influence：babies.
For this study,the neuroscientists showed 16 six-month-olds pictures of snakes and fish,and spiders and flowers.The idea was to match the scary animals with visually similar non-threats,to make sure it was really the snakes or spiders the babies would react to.And they did react,as eye-tracking software made clear：their pupils（瞳孔）were noticeably bigger when looking at the spiders and snakes,which corresponded to a much greater stress reaction.
But it's a success,since the results do suggest we have an inborn developed system in our brains that is specifically adapted to noticing,and not much caring for,snakes and spiders.
So as you're deciding on the decorations for Halloween,and trying not to scare your friends too much,keep in mind just how deep some fears go.And,if you have a baby you don't mind scaring just a little bit,the right decoration could be the perfect chance for some DIY neuroscience!



Why did the European neuroscientists choose babies to carry out the experiment？ ______

A. To prove the environment has no influence on our fears of snakes and spider.
B. To show that their brains are different from those of the adults.
C. To make it easy to control the environments of the babies.
D. To show most fears are learned from babies.

In the experiment,the scientists tested the babies by ______ .

A. making them look at the model snakes and spiders
B. monitoring their eyes' reactions to the pictures
C. stressing the babies with some software
D. making comparisons between different babies' pupils

We can learn from the text that ______ .

A. approximately one third of people dislike spiders and snakes
B. poisonous spiders and snakes have caused many problems
C. adults have learned their fears from their experiences
D. the experiment results indicate we fear spiders and snakes by nature

What does the author suggest in the last paragraph？ ______

A. Frightening decorations for Halloween should not go too far.
B. Snakes and spiders should be used for Halloween decorations.
C. The babies should not be scared on earth on Halloween.
D. It is better to turn to neuroscientists to decorate Halloween.

Shinrin-yoku means "forest bathing".Forest bathing doesn't mean you take a bath in the forest；rather,you simply go for a walk in the woods or a city park,where you slacken by using all your senses to experience nature.
Yoshifumi Miyazaki,from Chiba University,is among a growing number of scientists who have begun studying the science behind the effects of nature on human health.In his book Shinrin-yoku：The Japanese Art of Forest Bathing.Miyazaki explains the techniques of forest bathing.
Miyazaki has an interesting theory about why shinrin-yoku is so effective.He points out that for more than 99.99% of the time,humans have lived in a natural environment.In fact,in 1800，only 3% of the world's population lived in cities,and by 2016，this figure reached 54%.This is only going to get worse；officials predict that by 2050，66% will live in cities.
This suggests we live in our modem society with bodies that are still used to the natural environment,he writes in the book,because "genes cannot change over just a few hundred years".The science behind the research studies he presents in the book makes a convincing case that forest bathing is an effective method for reducing stress in today's world.
Now city planners are becoming increasingly aware of the importance of nature and are creating new kinds of "parks" out of empty spaces.There're also more city gardens where people can grow vegetables.For kids,kitchen gardens in schools are becoming popular.As Miyazaki stresses,you don't have to find a formal park or garden to practice shinrin-yoku.Instead,you can enjoy the effects of nature wherever there're plants.
Better yet,he says,we can bring nature closer to where we spend most of our time.Miyazaki's research has shown that just increasing the amount of plants in a room can affect the relaxation benefits of the room.What's more,even when people simply look at flowers,their bodies relax and stress levels decrease.



What does the underlined word in Paragraph 1 mean？ ______

A. Behave.
B. Entertain.
C. Sleep.
D. Relax.

How does the author mainly develop the third paragraph？ ______

A. By giving examples.
B. By listing figures.
C. By making remarks.
D. By presenting research findings.

Why does forest bathing work effectively according to Miyazaki？ ______

A. Human genes can change easily.
B. Nature is part of the modem society.
C. Human body can integrate into nature.
D. People can always get excited in nature.

Which of the following will Miyazaki agree on forest bathing？ ______

A. It is easy to operate.
B. It is meant for gardeners.
C. It is unaffordable in the city.
D. It is inconvenient to practice.

As Internet users become more dependent on the Internet to store information, are people remembering less？ If you know your computer will save information, why store it in your own personal memory, your brain？ Experts are wondering if the Internet is changing what we remember and how.
In a recent study, Professor Betsy Sparrow conducted some experiments. She and her research team wanted to know if the Internet is changing memory. In the first experiment, they gave people 40 unimportant facts to type into a computer. The first group of people understood that the computer would save the information. The second group understood that the computer would not save it. Later, the second group remembered the information better. People in the first group knew they could find the information again, so they did not try to remember it.
In another experiment,the researchers gave people facts to remember,and told them where to find the information on the Internet. The information was in a specific computer folder（文件夹）. Surprisingly, people later remember the folder location（位置） better than the facts. When people use the Internet, they do not remember the information. Rather, they remember how to find it. This is called "transactive memory（交互记忆）".
According to Sparrow, we are not becoming people with poor memories as a result of the Internet. Instead, computer users are developing stronger transactive memories； that is, people are learning how to organize huge quantities of information so that they are able to access it at a later date. This doesn't mean we are becoming either more or less intelligent, but there is no doubt that the way we use memory is changing.



The passage begins with two questions to ______ .

A. introduce the main topic
B. show the author's attitude
C. describe how to use the Internet
D. explain how to store information

What can we learn about the first experiment？ ______

A. Sparrow's team typed the information into a computer.
B. The two groups remembered the information equally well.
C. The first group did not try to remember the information.
D. The second group did not understand the information.

In transactive memory, people ______ .

A. keep the information in mind
B. change the quantity of information
C. organize information like a computer
D. remember how to find the information

What is the effect of the Internet according to Sparrow's research？ ______

A. We are using memory differently.
B. We are becoming more intelligent.
C. We have poorer memories than before.
D. We need a better way to access information.

Energy drinks aren't technically a "food". That's not to trash them - it's just a fact,and an important one at that. The Food & Drug Administration regulates all products defined as food to ensure they're safe for human consumption. Coffee drinks and soda, for instance, aren't allowed to be too high in caffeine in case they cause heart problems. But energy drinks are classified as supplements,which means they're unregulated. Hence, manufacturers are free to add as much caffeine inside a single can as they please. They can even mix caffeine with other stimulants（兴奋剂）in such a way that could cause cardiovascular or nervous system problems.
That's why physicians have been trying to investigate what the health effects of these caffeinated drinks might be. A new study showing that a single drink can diminish blood vessel （血管）function is making headlines, but similar findings have been increasing for years now.
A lot of the concern about these drinks comes from their high concentrations of stimulants. It's entirely possible to overdose on caffeine alone, and in combination with guarana, another stimulant, smaller amounts might have severe effects. Overdosing on caffeine doesn't necessarily result in death, but it can cause heart palpitations（心悸），nausea, vomiting, and hypertension. The WHO study also reports that adults who consume energy drinks may be increasing their risk of hypertension and type 2 diabetes.
Despite the WHO's recommendation that caffeine content be limited per beverage,energy drinks in the U. S. are still totally unregulated and will remain that way unless they get reclassified as a food. They may not be dangerous in small quantities,but nothing about them is healthy. Switch to coffee or tea,both of which will energize you in the morning and will be much harder to overdo it with. Or you could just go ahead and work on kicking your caffeine habit for good.



Why energy drinks are hard to regulate？ ______

A. Because they contain a lot of caffeine.
B. Because they cause heart problems.
C. Because they are not categorized as food.
D. Because they are allowed to be high caffeine.

What does the underlined word "That" in Paragraph 2 mean？ ______

A. A new study shows that energy drinks are harmful to humans.
B. As for now, energy drinks are not regulated in the United States.
C. Physician are going to evaluate the effect of energy drinks in the following studies.
D. Energy drinks together with other harmful ingredients could damage one's well-being.

Which of the following statements about energy drinks is TRUE？ ______

A. Overdosing on caffeine directly contributes to death.
B. Energy drinks play a negative role on affecting people's well-being.
C. People won't get addicted to caffeine only by consuming energy drinks.
D. Adults' consuming energy drinks may increase the possibility of the risk of diabetes.

What's the author's attitude towards energy drinks？ ______

A. Favorable.
B. Ambiguous.
C. Disapproving.
D. Indifferent.

Magic is a form of entertainment that is based on pretending to do things that are impossible. The magician is a specially trained actor. He tries to make the audience believe that he has the power to do things which are against the laws of nature.
Magic shows are entertaining as long as the audience does not discover how the tricks are done. The magician usually depends on his skill with his hands, on his knowledge of psychology, and, sometimes, on mechanical devices（机械装置）. Since magic performance is meant to trick people, the use of psychology is important. The magician must keep people from noticing all the movements of his hands and from thinking about the secret parts of his equipment. He must also lead the audience to draw false conclusions. The magician's success depends on the fact that many things seen by the eye are not the things that matter.
Two basic magic tricks are making objects seem to appear and making objects seem to disappear. A combination of these two tricks makes for some interesting effects. For example, the magician puts a small ball under one of several cups. The ball then seems to jump from one cup to another or to change colour. What actually happens is that the magician, employing quick hand movements or a mechanical device, hides one ball. While doing this he talks to the audience and waves a brightly coloured cloth with one hand. The audience is too busy watching the cloth and listening to the magician's words to notice that his other hand is hiding the ball.
Another favourite trick is to cut or burn something,and then make it appear whole again. What actually happens is that the magician makes the cut or burned object disappear by quickly hiding it while the audience watches something else. Then he "magically" makes it appear whole again by displaying another object that has not been cut or burned.



What is the author's main purpose in writing the text？ ______

A. To promote a magic show.
B. To teach people to be magicians.
C. To explain the art of magic.
D. To praise the talents of magicians.

Which of the following is important for a successful magic trick？ ______

A. Moving stage equipment.
B. Directing the audience's attention.
C. Applying high technology.
D. Keeping the performance in secret.

What does the author focus on in the last two paragraphs？ ______

A. Providing examples.
B. Making a summary.
C. Drawing comparisons.
D. Explaining a concept.

What can we infer from the text？ ______

A. Mechanical devices are expensive.
B. Most magicians employ assistants.
C. It takes practice to perform magic.
D. Small objects are magicians' favourite.

Most Chinese film fans will be familiar with the name of Zhang Yimou,one of the country's most successful and internationally praised film directors. Films such as Raise the Red Lantern and Hero brought his films to the attention of the West, and succeeded in creating a new audience for Chinese cinema.
Born in 1951 ， Zhang Yimou spent his youth working on farms and in factories, during which time he developed a love of photography. When the Beijing Film Academy reopened, Zhang Yimou became one of the first students. After graduation, his career as director of photography began.
In 1987 Zhang directed his first film, Red Sorghum, which was a great success. In 1992，Zhang's Raise the Red Lantern was nominated （提名）for an Oscar for Best Foreign Film. Film fans were attracted by the great visual （视觉的） beauty of Zhang's films, and by the importance in his stories of his heroines.
In 2002， Zhang made Hero, a martial（武打）arts film set in ancient times but told in a completely different, modem style. Hero achieved great success in the West.
In 2004， Zhang made Houses of the Flying Dragons, another martial arts film, which Zhang described as being " much more like a modern romantic story" in which the characters devote every other thing for love.
Perhaps one of the keys to Zhang's success as a filmmaker is the fact that his preparations for a film are so detailed. He has said before he starts a project he discusses everything in detail with every single person involved in the film. The result is that when filming starts, everyone understands what is wanted. It is certain that Zhang has many more years of successful filmmaking.



When did Zhang Yimou turn film maker？ ______

A. In his forties.
B. In his thirties.
C. After 1987.
D. While at college.

Which was Zhang Yimou's second martial films？ ______

A. Red Sorghum.
B. Houses of the Flying Dragons.
C. Hero.
D. Raise the Red Lantern.

What makes Zhang Yimou a successful director？ ______

A. His strictness with the actors.
B. The good personal friendship.
C. His carefulness in filmmaking.
D. The details he adds to his film.

What does the author think of Zhang Yimou？ ______

A. He'll direct Beijing Winter Olympic Games.
B. Many film directors do as well as him.
C. His future films will be more impressive.
D. He'll continue to make good films.

Every year,the Joint Mathomatics Meeting brings more than 5，000 math lovers together. It's the largest math meeting in the world. In January 2019， mathematicians flew to the meeting in Baltimore,Md.，to learn about new ideas and talk about their work. Many even came to admire the latest in mathematical art.
The meeting included an entire art exhibition. Visitors felt amazed at sculptures made from metal,wood and folded paper. One was based on a supersized Rubik's cube. Many like triangles, were arranged in strange and surprising sizes and colors. The collection also included drawings and paintings inspired by the study of numbers, curves （曲线） and patterns.
Art and math may seem like a strange pairing. People usually experience art through their senses. They see a painting or listen to music. If this art moves them, they will have an emotional response. Working at math problems is usually viewed as something you think about-not feel. But connections between the two fields reach far back in time. Sculptors and architects in some ancient civilizations included numbers and math ideas into their works.
Henry Segerman is a mathematician and artist. When he was in high school,in England,he was good at math and art. But he had to choose. "I went in the math direction back then," he says. He thought it difficult to succeed as an artist.
Still,Segerman's math studies led him into the visual areas of math,such as geometry. In 2015， Segerman and some math art friends created a virtual-reality artwork. Participants can put on a pair of VR goggles to float around and through four-dimensional shapes. Art makes it possible to interact （互动） with these shapes, which would be impossible to create in our three-dimensional world. As beautiful as it is to see,Segerman's work also offers a new view on mathematical ideas.



What distinguishes the exhibits at the meeting？ ______

A. They are art works with high technology.
B. They reflect the long history of math.
C. They are made based on math ideas.
D. They turn visual art into specific math.

What does the underlined sentence in paragraph 3 mean？ ______

A. They seem extremely hard to appreciate.
B. They're experienced in different ways.
C. They've been separated since ancient times.
D. They fail to bring about people's responses.

What can we learn from Henry Segerman's story？ ______

A. Math learning promotes the creation of art.
B. Math makes art easier to understand.
C. Math is actually the origin of fine art.
D. One can't easily succeed in math.

What is the main idea of the text？ ______

A. Real artists will stand the test of math.
B. Math and art turns out a great combination.
C. Modern artists turn into mathematicians.
D. Artists make math make a kind of art.