选择知识点

People believe that climbing can do good to health.Where can you learn the skill of climbing then？If you think that you have to go to the mountains to learn how to climb,you're wrong.Many Americans are learning to climb in city gyms（体育馆）.Here,people are learning on special climbing walls.The climbing wall goes straight up and has small holding places for hands and feet.
How do people climb the wall？To climb,you need special shoes and a harness（保护带）around your chest to hold you.There are ropes（绳索）tied to your harness.The ropes hold you in place so that you don't fall.A beginner's wall is usually about 15 feet high,and you climb straight up.There are small pieces of metal that stick out for you to stand on and hold on to.Sometimes it's easy to see the next piece of metal.Sometimes,it's not.The most difficult part is to control your fear.It's normal for humans to be afraid of falling,so it's difficult not to feel fear.But when you move away from the wall,the harness and the ropes hold you,and you begin to feel safe.You move slowly until you reach the top.
Climbing attracts people because it's good exercise for almost everyone.You use your whole body,especially your arms and legs.This sport gives your body a complete training.When you climb,both your mind and your body can become stronger.



The word "training" underlined in the last paragraph most probably means ______ .

A. excitement.
B. tiredness.
C. settlement.
D. workout.

The most difficult thing to do in wall climbing is ______ .

A. to tie ropes to your harness
B. to control your fear
C. to climb straight up
D. to move away from the wall

Which of the following is true？ ______

A. It's easy for people not to feel fear while climbing.
B. You have to go to the mountains to learn how to climb.
C. To climb wall,you only need a harness around your chest to hold you.
D. Climbing is good exercise for both your body and mind.

Why does the author write this passage？ ______

A. To introduce the sport of wall climbing.
B. To encourage people to climb mountains.
C. To prove the basic need for climbing.
D. To tell people where to find gyms.

The idea of using a public bathroom with see-through walls may sound like a nightmare.But a famous Japanese architect is hoping to change that view,using new technology to make restrooms in Tokyo parks more appealing.
"There are two things we worry about when entering a public restroom,especially those located at a park," according to architect Shigeru Ban's firm. "The first is cleanliness,and the second is whether anyone is inside. "
The newly-invented transparent walls can turn off both of those worries,Ban says,by showing people what waits for them inside.After users enter the restroom and lock the door,the room's walls turn a powdery pastel（彩色蜡笔的，柔和的）shade—and are no longer see-through.
Ean's transparent facilities are sure to make for great conversation among visitors to the park—and they'll stand out even more after dark. "At night,the facility lights up the park like a beautiful lantern," the architect's website says.
The group is behind the Tokyo Toilet project,enlisting（招募）world-famous architects to create toilets "like you've never seen." The project's eye-catching toilets are part of a plan to put people at ease when visiting a public bathroom.The project may seem silly,but the 16 architects who are reimagining public toilets are some of the brightest names in Japanese architecture.The list includes four Pritzker Prize winners—Ban,Toyo Ito,Tadao Ando and Fumihiko Maki一along with international stars such as Kengo Kuma and Sou Fujimoto.The fashion designer Nigo is also contributing.
Ban's colorful public bathrooms opened to the public this month in two parks：Yoyogi Fu kamachi Mini Park and Haru--no--Ogawa Community Park.Others will be opening in coming months.



Why are people often worried before entering a public restroom？ ______

A. It's not always clean.
B. It's usually at a huge distance.
C. Its lock is usually useless.
D. It's always occupied.

What does the underlined word "transparent" mean in the third paragraph？ ______

A. Full of bright colors.
B. Not easy to see through.
C. Easy to see through.
D. Thick and strong.

What do we know about the project from the last two paragraphs？ ______

A. It's impractical and silly.
B. It's rewarding and famous.
C. It has won the Pritzker Prize.
D. It's the fruit of collective wisdom.

Which of the following can be the best title for the text？ ______

A. Should the public restrooms be upgraded？
B. The new high-tech walls of public restrooms are coming
C. How do we live with see-through public facilities？
D. Some famous architects designed a silly project.

Warming temperatures and changing rainfall patterns may reduce diet diversity（多样性）among children around the world and may even destroy efforts to improve food security.Researchers analyzed the results of health surveys from more than 107，000 children in 19 countries— in Asia；North,south-east and West Africa；as well as Central and South America.
In the surveys,the diversity of a child's diet was quantified（量化）based on their intake of foods from different food categories,including grains,milk products and meat.On average,3.2 food categories out of 10 were consumed by the children aged 5 and under,but the situation varied from country to country.Children in Colombia ate from 4.8 food categories on average,while those in Lesotho ate from just 1.8.
To study whether climate affected the diversity of the children's diets,the researchers linked the results from each country to 30 years of rainfall and temperature data in the surveyed areas.They found that long-term higher temperatures were associated with lower diet diversity for children everywhere except Central America.
There were also shorter-term trends.In North Africa and South America,there was typically a reduction in diet diversity in countries that experienced above-average temperatures the year before the survey.In Central America and West Africa,diets typically became more diverse in countries that experienced above-average rainfall in the previous year.In some countries,the researchers say that the negative effects of climate change on diet diversity was great,and that they may even destroy efforts to improve food security.
Diet diversity is a useful standard for areas with high rates of child malnutrition（营养不良），says Daniel Mason D'Croz,an Australian researcher. "Children need a fruit or a vegetable or animal product besides the rice— that's an important thing for people to know," he says.And he also added that recent follow-up studies have provided more authoritative evidence of the effect of climate change on reducing diet diversity.



Why did researchers study the data of rainfall and temperature in the surveyed areas？ ______

A. To learn the diversity of a child's diet from different countries.
B. To confirm the negative effects of climate on food production.
C. To explore the effects of climate on the children's diets diversity.
D. To link the rainfall and temperature data to lower food categories.

What does the underlined word "they" in Paragraph 4 refer to？ ______

A. The researchers.
B. Some countries.
C. The negative effects.
D. Above-average temperatures.

What can we infer from the last two paragraphs？ ______

A. Children need fruits or vegetables except the rice.
B. Reducing diet diversity may cause child malnutrition.
C. Higher temperatures will make the diet more diverse.
D. Above-average rainfall leads to reducing diet diversity.

What could be the best title for the text？ ______

A. Children's Diet Will Be Influenced by Rainfall
B. Food Security Varies from Country to Country
C. Climate May Affect the Diversity of Children's Diet
D. Scientists Are Making Efforts to Change Children's Diet

Thanks to its harsh environment,Antarctica remained largely untouched by humans for many millennia（千年），allowing a thriving ecosystem to evolve.However,since the 1990s,the last true wilderness on the planet is becoming an increasingly popular destination for adventure-seeking tourists.Now,a new study declares that the visitors may be leaving behind harmful bacteria which could devastate all of the area's native bird population.
Humans can infect animals with illnesses such as the flu.Researchers,however,believed that the Antarctic animals were immune to the danger due to the continent's extreme weather.However,microbiologist Marta Cerda-Cuellar was not convinced.She and some colleagues decided to examine waste samples from Antarctic birds for evidence of human bacteria.To ensure the waste was not polluted,the scientists had to collect it from the birds themselves.
The results of their study revealed the presence of several types of human bacteria in the bird waste.This included a common strain（品种）of bacteria that causes food poisoning in humans.The researchers say the bacteria strains were resistant to commonly-used human antibiotics,indicating they were brought in by the visitors,rather than migratory birds.
"These strains,which are a common cause for infections in humans and livestock,do not usually cause death outbreaks in wild animals," says Gonzalez Solis. "However,the emerging of invasive pathogens（病原体）that arrive to highly sensitive populations could have severe consequences and cause the local collapse and extinction of some populations. " The researcher also fears the presence of these bugs could foreshadow（预示）the arrival of other,more deadly,pathogens as the number of tourists people increases.
Experts believe the only way to prevent the mass destruction of the birds is to impose stricter regulations or,at least,put the ones already in place into effect.For example,while the Antarctica Treaty requires visitors to carry their waste back home to safeguard the pristine（原始纯净的）environment,the regulation is rarely enforced.Fortunately,nowadays some officials are taking steps to save the vulnerable birds before it's too late.



What problem is Antarctica facing according to Paragraphs 1&2？ ______

A. The increasing number of birds.
B. The worsening wilderness.
C. The replaced native bird species.
D. The spread of infectious illnesses.

What does the underlined word "devastate" mean？ ______

A. Reject.
B. Protect.
C. Destroy.
D. Benefit.

What do we know about the waste samples from Antarctic birds the scientist collected？ ______

A. There were several types of human bacteria in them.
B. Migratory birds brought these strains of bacteria in.
C. The strains usually cause death outbreaks in wild animals.
D. The invasive pathogens will become more deadly ones soon.

What is the author's attitude towards the future of bird population in Antarctica？ ______

A. Indifferent.
B. Doubtful.
C. Ambiguous.
D. Optimistic.

Off the coast of Formentera,an island,lives seagrass that stretches 15 kilometres.The seagrass,covering several hectares,is made up of a single organism.The grasses are also long-lived,for tens or hundreds of thousands of years.Along with two other kinds of coastal ecosystems—mangrove swamps（红树沼泽）and tidal marshes,seagrass meadows are particularly good at taking carbon dioxide from the air.
This role was highlighted in a report,which was published on March 2nd by UNESCO，on blue carbon—the carbon taken in by Earth's oceanic and coastal ecosystems.In total around 33 billion tons of carbon dioxide,about three-quarters of the world's emissions（排放）in 2019，are locked away in the planet's blue carbon sinks（碳汇）.Research by Carlos Duarte,the report's author and a marine ecologist,has shown that one hectare of seagrass can suck as much carbon dioxide each year as 15 hectares of rainforest.
One reason that blue—carbon ecosystems make such effective sinks is that underwater forests are thicker than the land-based woods.They can also trap floating pieces and organic matter,which settles on the sea floor and can double the amount of carbon stored away.They have another advantage,too.Climate change is leading to more wildfires around the world.As forests burn,their carbon stocks are released back into the atmosphere.Unlike forests on land,blue-carbon ecosystems do not burn.
Blue-carbon ecosystems may not be fired,but they remain affected to other sorts of disasters.In May 2020 hurricane Amphan destroyed 1，200 square kilometres of mangrove forest.A marine（海洋的）heatwave in Australian waters in 2010 and 2011 damaged around one third of the world's largest seagrass meadow in Shark Bay. "Mangrove forests can weaken or control waves and provide natural barriers to storm surges.Protecting and expanding them,then,appears to be a must," said a marine biologist.



What does the second paragraph mainly talk about？ ______

A. The real definition of blue carbon.
B. The special features of the seagrass.
C. The doubt about the blue-carbon ecosystems.
D. The capacity of the blue-carbon ecosystems to store carbon.

Why can the blue-carbon ecosystems make such effective sinks？ ______

A. They aren't influenced by natural disasters.
B. They have great ability to absorb carbon.
C. Their carbon stocks are released back.
D. There are more underwater animals.

What do the marine biologist's words mean？ ______

A. Mangrove forests are too strong to be broken.
B. Mangrove forests can strengthen waves.
C. Humans should preserve blue-carbon ecosystems.
D. Blue carbon ecosystems can be fired.

What is the best title for the text？ ______

A. Plants in the Ocean Are Better at Storing Carbon
B. The Grasses Can Store More Carbon Than Your Expectation
C. Mangrove Forests Can Control Waves Efficiently
D. Blue-Carbon Ecosystem Are Expanding Much Faster

Droughts（干旱）caused by global climate change have led to drop in wheat production,a worldwide shortage and high food prices around the world.The global wheat supply is at its lowest point in 50 years,with only an estimated 10 weeks of supply left.This has been one factor pushing the prices of bread,beer and other wheat-containing foods steadily higher.According to Hilton Dinner,a bakery owner from Edmonton,Canada,the price of flour has more than doubled over the past eight months.In 19 years of business,Dinner said,he has never seen prices rise like this.
"Prices creep up seasonably," he said. "They might go up 10 percent,then down 5 percent.They never go back to where they started,but they creep.This is not creeping,this is drastic."
Also to blame for the global wheat shortage is the rising population,coupled with increasing meat consumption worldwide.This has led to the increasing diversion of grain to animal feed.
Analysts anticipate that the shortage may be resolved within 12 months,as farmers pull fallow land into wheat production.But even when the shortage resolves,food prices are only expected to keep climbing due to other factors,such as high energy and shipping costs.
"It's not something that's going to go away," Dinner said. "Food in general is going to go up.As wheat goes up,so does the price of eggs and chicken because they eat grain-based feed.It affects people who can't afford to pay more for their food."
Public health experts have expressed concern about the effect that rising food prices have on the poor.The United Nations recently reported that in 2007，the cost of food imports in the world's neediest countries increased 24 percent to a total of ＄107 billion.



The indirect reason for a drop in wheat production is ______ .

A. the drought
B. the global climate change
C. the shipping cost
D. the rising population

According to the first paragraph,the prices of wheat products rise ______ .

A. suddenly
B. gradually
C. slowly
D. rapidly

The wheat shortage may disappear if ______ .

A. the empty lands are used to plant wheat
B. the shipping costs are falling down
C. chickens don't feed on wheat any more
D. beer isn't made from wheat any more

The passage mainly tells us that ______ .

A. poor people can't afford food
B. the rising population leads to high food prices
C. the global climate change causes wheat shortage
D. food prices are going to go down

Race walking shares many fitness benefits with running,research shows,while most likely contributing to fewer injuries.It does,however,have its own problem.
Race workers are conditioned athletes.The longest track and field event at the summer Olympics is the 50-kilometer race walk,which is about five miles longer than the Marathon.But the sports rules require that a race walker's knees stay straight through most of the leg swing and one foot remain in contact（接触）with the ground at all times.It's this strange form that makes race walking such an attractive activity,however,says Jaclyn Norberg,an assistant professor of exercise science at Salem State University in Salem,Mass.
Like running,race walking is physically demanding,she says.According to most calculation,race walkers moving at pace of six miles per hour would burn about 800 calories（卡路里）per hour,which is approximately twice as many as they would burn walking,although fewer than running,which would probably burn about 1，000 or more calories per hour.
However,race walking does not pound the body as much as running does,Dr.Norberg says.According to her research,runners hit the ground with as much as four times their body weight per step,while race walkers,who do not leave the ground,create only about 1.4 times their body weight with each step.
As a result,she says,some of the injuries associated with running,such as runner's knee,are uncommon among race walkers.But the sport's strange form does place considerable stress on the ankles and hips,so people with a history of such injuries might want to be cautious in adopting the sport.In fact,anyone wishing to try race walking should probably first consult a coach or experienced racer to learn proper technique,she says.It takes some practice.



Why are race walkers conditioned athletes？ ______

A. They must run longer distances.
B. They are qualified for the Marathon.
C. They have to follow special rule.
D. They are good at swinging their legs.

What advantage does race walking have over running？ ______

A. It's more popular at the Olympics.
B. It's less challenging physically.
C. Its more effective in body building.
D. It's less likely to cause knee injuries.

What is Dr.Norberg's suggestion for someone trying race walking？ ______

A. Getting experts' opinions.
B. Having a medical checkup.
C. Hiring an experienced coach.
D. Doing regular exercises.

Which word best describes the author's attitude to race walking？ ______

A. Skeptical.
B. Objective.
C. Tolerant.
D. Conservative.

From the loss of wildlife to rising sea levels,we're all well aware of the problems that climate change could cause.
But while it may seem like such issues won't affect most of us directly,it looks like future generations could grow up without something that many of us now take for granted：chocolate.
According to an essay published by the US National Oceanic and Atmospheric Administration,changes to the climate in the regions that produce cacao--the plant from which chocolate is produced--may mean that it will soon become extinct.
Most of the world's cacao grows in countries close to the equator（赤道），with over half of it growing in the African nations of Ghana and Ivory Coast.It's predicted that by 2050，climate change will have accelerated the rate at which temperatures in these countries rise,making it extremely difficult for cacao to grow there.
The problem doesn't lie in increased heat,however,but in lower humidity（湿度），as it's believed that rainfall will stay at the same level if the temperature rises.
"In other words,as higher temperatures squeeze more water out of soil and plants,it's unlikely that rainfall will increase enough to offset the moisture（水分）loss," Michon Scott,the essay's author,wrote.
To help fight this problem,researchers from Berkeley University in the US are working on changing the DNA of cacao plants to allow them to survive in dryer conditions by using gene editing technology,according to US News.In the meantime,US company Mars,one of the world's biggest manufacturers of chocolate products,announced in January that it would spend ＄1 billion （6.33 billion yuan） to help reduce the effects of climate change.
"This is a world issue,and it requires everyone to work together," Mars spokesperson Barry Parkin told Business Insider.
The message here is that if we all do our part,we may be able to prevent some of the worst impacts of climate change.Or if we're unlucky,chocolate will become a thing of the past.



What could make it hard for cacao to grow around the equator in the future？ ______

A. the higher temperatures there
B. the higher humidity there
C. the increase in rainfall there
D. the moisture loss in the soil there

What did Barry Parkin suggest？ ______

A. A thousand-mile journey begins with the first step.
B. Always prepare for a rainy day.
C. United we stand；divided we fall.
D. Wish for the best；prepare for the worst.

What can we learn from the passage？ ______

A. UC Berkeley is trying to find a substitute for cacao.
B. Cacao can only be found in most African countries.
C. Climate changes can be controlled if we are lucky.
D. Mars will financially support the fight against climate changes.

What may be the best title of this text？ ______

A. Chocolate could become history
B. Work together to fight climate change
C. How do we grow cacao in the future？
D. The history of chocolate.

Hundreds of millions have rolled up their sleeves for the COVID-19 vaccine,but why haven't they rolled up their pants legs instead？Why do we get most shots in our arms？What's the science behind why we get most vaccines in our arm and does location matter？
Muscles make an excellent vaccine （疫苗） administration site because muscle tissue contains important immune （免疫） cells.These immune cells recognize the antigen （抗原），a tiny piece of a virus or bacteria introduced by the vaccine that stimulates an immune response.
In the case of the COVID-19 vaccine,the immune cells in the muscle tissue pick up these antigens and present them to the lymph nodes （淋巴结）.Injecting （注射） the vaccine into muscle tissue keeps the vaccine localized,allowing immune cells to sound the alarm to other immune cells and get to work.Once a vaccine is recognized by the immune cells in the muscle,these cells carry the antigen to lymph vessels,which transport the antigen-carrying immune cells into the lymph nodes.
Lymph nodes,key components of our immune system,contain more immune cells that recognize the antigens in vaccines and start the immune process of creating antibodies.
Croups of lymph nodes are located in areas close to vaccine administration sites.For instance,many vaccines are injected in the deltoid （三角肌） because it is close to lymph nodes located just under the armpit （腋下）.
Muscle tissue also tends to keep vaccine reactions localized at the injection site.If certain vaccines are injected into fat tissue,the chance of irritation and side effect increases because fat tissue has poor blood supply,leading to poor absorption of some vaccine components.Vaccines must be given in a muscle to avoid widespread side effect.
Yet another deciding factor in vaccine administration location is the size of the muscle as well as convenience.



Why did the author raised many questions in the first paragraph？ ______

A. People do have many questions about injecting the vaccine into arms.
B. The writer actually didn't know the answers of these questions.
C. The writer wanted to arouse readers' interest in reading the article.
D. The theory behind the vaccine injection is difficult to understand.

What's the advantage of getting vaccine shots in the muscle？ ______

A. Muscle tissue spread important immune cells easily.
B. Muscle tissue can stimulate an immune response.
C. The antigen can be recognized by muscle tissue easily.
D. Vaccine can stimulate a better immune response there.

What may the underlined word in the sixth paragraph mean？ ______

A. Common feeling of sorrow.
B. Abnormal sensitivity to stimulation.
C. Terrible wound in the muscle.
D. Absorption of vaccine components.

What may the article continue to present？ ______

A. The advantage of getting wide vaccine shots in arms.
B. How to prevent the wide spread of the COVID-19.
C. The size of muscle and convenience also location.
D. How to prevent the side effect of getting vaccine shots.

Do you know how it is when you see someone yawn and you start yawning too？Or how hard it is to be among people laughing and not laugh yourself？Well,apparently it's because we have mirror neurons（神 经元）in our brains.
Put simply,the existence of mirror neurons suggests that every time we see someone else do something,our brains imitate（模仿）it,whether or not we actually perform the same action.This explains a great deal about how we learn to smile,talk,walk,dance or play sports.But the idea goes further：mirror neurons not only appear to explain physical actions,they also tell us that there is a biological basis for the way we understand other people.
Mirror neurons can undoubtedly be found all over our brains,but especially in the areas which relate to our ability to use languages,and to understand how other people feel.Researchers have found that mirror neurons relate strongly to language.A group of researchers discovered that if they gave people sentences to listen to（for example：The hand took hold of the ball），the same mirror neurons were triggered as when the action was actually performed （in this example,actually taking hold of a ball）.
Any problems with mirror neurons may well result in problems with behavior.Much research suggests that people with social and behavioral problems have mirror neurons which are not fully functioning.However,it is not yet known exactly how these discoveries might help find treatments for social disorders.
Research into mirror neurons seems to provide us with ever more information concerning how humans behave and interact（互动）.Indeed,it may turn out to be the equivalent（相等物）for neuroscience of what
Einstein's theory of relativity was for physics.And the next time you feel the urge to cough in the cinema when someone else does—well,perhaps you'll understand why.



Mirror neurons can explain ______ .

A. why we cry when we are hurt
B. why we cough when we suffer from a cold
C. why we smile when we see someone else smile
D. why we yawn when we see someone else stay up late

The underlined word "triggered" in the third paragraph probably means" ______ ".

A. set off
B. cut off
C. built up
D. broken up

We can learn from the passage that mirror neurons ______ .

A. relate to human behavior and interaction
B. control human physical actions and feelings
C. result in bad behavior and social disorders
D. determine our knowledge and language abilities

What is the passage mainly about？ ______

A. Ways to find mirror neurons.
B. Problems of mirror neurons.
C. Existence of mirror neurons.
D. Functions of mirror neurons.