选择知识点

The idea of turning recycled plastic bottles into clothing is not new.During the last five years,a large number of clothing companies,businesses and environmental organizations have started turning plastics into fabric to deal with plastic pollution.But there's a problem with this method.Research now shows that microfibers could be the biggest source of plastic in the sea.
Dr.Mark Browne in Santa Barbara,California,has been studying plastic pollution and micro-fibers for 10 years now.He explains that every time synthetic（合成的）clothes go into a washing machine,a large number of plastic fibers fall off.Most washing machines can't collect these microfibers.So every time the water gets out of a washing machine,microfibers are entering the sewers and finally end up in the sea.
In 2011，Browne wrote a paper stating that a single piece of synthetic clothing can produce more than l,900 fibers per wash.Browne collected samples from seawater and freshwater sites around the world,and used a special way to examine each sample.He discovered that every single water sample contained microfibers.
This is bad news for a number of reasons.Plastic can cause harm to sea life when eaten.Studies have also shown that plastic can absorb other pollutants.
Based on this evidence,it may seem surprising that companies and organizations have chosen to turn plastic waste into clothing as an environmental "solution".Even though the science has been around for a while,Browne explains that he's had a difficult time getting companies to listen.When he asked well-known clothing companies to support Benign by Design-his research project that seeks to get clothes that have a bad effect on humans and the environment out of the market,Browne didn't get a satisfying answer.Only one women's clothing company,Eileen Fisher,offered Browne funding.



What has happened during the past five years？ ______
A. Fabric has become much stronger.
B. Plastic pollution has been less serious.
C. Microfibers have been greatly improved.
D. Many plastic bottles have been reused.

What does Browne think of washing synthetic clothes？ ______

A. It is worsening environmental problems.
B. It is adding microfibers to the clothes.
C. It is making synthetic clothes last longer.
D. It is doing great damage to washing machines.

What can be inferred about Browne's Benign by Design research project？ ______

A. It has achieved great success.
B. It hasn't got anything done.
C. It is facing some difficulties.
D. It is known to very few people.

Where is the text most likely from？ ______

A. A novel.
B. A magazine.
C. A diary.
D. A guidebook.

Evidence of a worm-like creature about the size of a grain of rice has been uncovered in South Australia,and researchers believe it is the oldest ancestor on the family tree that includes humans and most animals.The creature lived about 535 million years ago. It is considered to be an evolutionary step forward for early life on Earth.
Researchers have been trying to find evidence of the common ancestor of most animals.Developing its body structure and organization successfully allowed life to move in specific,purposeful directions.This includes everything from worms and dinosaurs to amphibians（两栖动物）and humans.But for our common ancestor,they knew that fossils（化石）of the tiny,simple creatures they imagined would be nearly impossible to find because of its size and soft body.Then,they turned to fossilized burrows,dated to the Ediacaran Period,found in South Australia.
For 15 years,scientists knew the burrows were created by the creature.There was no evidence of what made the burrows and lived in them until researchers decided to take a closer look at the burrows.Geology professor Mary Droser spotted impressions shaped like ovals near the burrows.
A 3-D laser scan revealed the impressions containing evidence of a body shaped and sized like a rice grain,with a noticeable head and tail which suggested it had muscles.The muscles would have enabled the creature to move and create the burrows,like the way a worm moves.And the size of the creature matched with the size of the burrows they found.
The researchers involved in the study named the creature Ikaria wariootia.The first name translates as "meeting place" in the Adnyamathanha language.Adnyamathanha is the name of Australian people that live in the area where the fossil was found.



What does the underlined word "It" mean in the first paragraph？ ______

A. A worm-like creature.
B. A grain of rice.
C. A family tree.
D. An evolutionary step.

What did the researchers do during the study？ ______

A. They developed the creature in the expected way.
B. They studied a large number of worms and dinosaurs.
C. They observed the burrows close up.
D. They went back to the Ediacaran Period some years ago.

What inspired the scientists to explore the origin of the burrows？ ______

A. A 3-D laser scan.
B. The impressions.
C. Some good ovals.
D. More burrows.

What does the text mainly tell us？ ______

A. The researchers worked very hard in the burrow.
B. The worm-like creature may be animals' ancestor.
C. It is very difficult to name a new kind of creature.
D. Australian people like fossils of many creatures.

Declining mental function is widely regarded as a problem of old age,but certain aspects of brain function actually begin their decline in young adulthood,a new study suggests.
The study,which followed more than 2，000 healthy adults between the ages of 18 and 60，found that certain mental functions—including measures of abstract reasoning,mental speed and puzzle-solving—started to dull as early as age 27.The dip in memory,meanwhile,generally became apparent around age 37.
On the other hand,indicators of a person's accumulated knowledge—like performance on tests of vocabulary—kept improving with age,according to the findings.
The results do not mean that young adults need to start worrying about their memories.Most people's minds function at a high level even in their later years,according to researcher Timothy Salthouse.
"These patterns suggest that some types of mental flexibility decrease relatively early in adulthood,but that the knowledge one has,and the effectiveness of integrating（整合）it with one's abilities,may increase throughout all of adulthood if there are no diseases," Salthouse said.
The study included healthy,educated adults who took standard tests of memory and reasoning over a period of seven years.In general,Salthouse and his colleagues found,certain aspects of cognition（认知能力） generally started to decline in the late 20s to 30s.
The findings threw light on normal age-related changes in mental function,which could aid in understanding the process of dementia（痴呆）. "By following individuals over time," Salthouse said,"we gain insight in cognition changes,and may possibly discover ways to slow the rate of decline."
The researchers are currently analyzing the study participants' health and lifestyle to see which factors might influence age-related cognitive changes.



What is the common view of mental function？ ______

A. It varies from person to person.
B. It gradually expands with age.
C. It weakens in one's later years.
D. It indicates one's health condition.

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

A. Improvement.
B. Decline.
C. Difference.
D. Breakthrough.

For adults in their 40s,which of the following may improve as they age？ ______

A. Their decision-making abilities.
B. Their abstract reasoning abilities.
C. The sympathy they show people around.
D. The amount of knowledge they have.

According to Salthouse,their study may help us ______ .

A. find ways to improve our memories
B. find ways to slow down our mental decline
C. understand the complex process of mental functioning
D. understand the relation between physical and mental health

Rain is vital to life on Earth.However,rain isn't just made of water anymore – it's partly made of plastic.
Millions of tiny pieces of plastic,called microplastics,are wandering around Earth's atmosphere and traveling across entire continents,according to a study published in the journal Proceedings of the National Academy of Sciences on April 12.Another study,published in the journal Science in June 2020，has revealed that every year more than 1，000 tons of the particles（颗粒）- equivalent to over 120 million plastic bottles - fall in rain.
Microplastics are plastic particles less than 5 millimeters in diameter（直径）and come from a number of sources.Plastic bags and bottles released into the environment break down into smaller and smaller bits.Some microplastics are manufactured deliberately to provide abrasion（研磨）in a host of products,such as toothpaste and cleansers,according to the Daily Mail.Another major source is your washing machine.When you wash synthetic（合成的）clothing,tiny microfibers get flushed（冲掉）away with the wastewater.Even though the water is treated by a wastewater plant,the microplastics remain,and they are released into the sea,according to American magazine Wired.
Plastic rain may remind people of acid rain,but the former is far more widespread and harder to deal with.The tiny particles,too small to be seen with the naked eye,are collected by the wind from the ground.They are so light that they stay in the air to be blown around the globe.As they climb into the atmosphere,they are thought to act as nuclei（核心）around which water vapor（水蒸气）condenses（凝结）to form clouds.Some of the dust falls back to land in dry conditions,while the rest comes down as rain,according to the Daily Mail.
Microplastics have been found everywhere you can imagine.From fish and frogs to mice and mosquitoes,their bodies have been found,on average,to contain 40 pieces of microplastic,reported Daily Mail.As the top of the food chain,humans are exposed to microplastics,too. "We live on a ball inside a bubble," microplastic researcher Steve Allen at University of Strathclyde,Scotland,told Wired. "There are no borders,there are no edges.It（plastic rain）raining on the land and then getting blown back up into the air again,to move somewhere else.There's no stopping it once it's out."



What does paragraph 3 mainly talk about？ ______

A. How microplastics should be handled.
B. How microplastics are used widely.
C. How microplastics pollute water.
D. How microplastics come into being.

What do we know about microplastics？ ______

A. They are light and can be easily dealt with.
B. They result in both acid rain and plastic rain.
C. They have a diameter of at least 5 millimeters.
D. They have nearly affected the whole food chain.

What do Steve Allen's words mean in the last paragraph？ ______

A. No place is safe from microplastic pollution.
B. The atmosphere possesses the capacity to self-cleanse.
C. Countries should work together to fight plastic pollution.
D. It is important to remove microplastics somewhere else.

What's the main purpose of the article？ ______

A. To compare acid rain and plastic rain.
B. To warn people of the dangers of microplastics.
C. To call on people to reduce using plastic products.
D. To introduce the sources and effects of microplastics.

An important but rarely discussed problem of health care reform is how to care for our aging population as people continue to live longer.According to a new study from the MacArthur Research Network on an Aging Society,by 2050 Americans may live 3.1 to 7.9 years longer than the government expects.That would mean women would live 89 to 93 years and men 83 to nearly 86 years.The researchers base their conclusion on "rapid advances in biomedical（生物医药）technology that delay the start and progression of major deadly diseases or that slow the aging process."
While this is good news,especially for the young,the life expectancy,which is in excess of（超过）the government's estimates,would raise costs sharply for Medicare and Social Security.If the study's predictions are accurate,the total cost for those two programs through 2050 could be between ﹩3.2 trillion and ﹩8.3 trillion higher than the US Census Bureau（人口普查局）and the Social Security Administration currently expect.
"And that's only the beginning.With anticipated scientific breakthroughs in coming decades,people could eventually live to 150 years of age." says Dr.Steven Joyal,an official of the Life Extension Foundation,which is a nonprofit organization that promotes research on how we can live longer and healthier.The MacArthur paper,in fact,says that some experts believe the average life expectancy could hit 100 by 2060.
"What's more"，Joyal says,"the conquest（战胜）of disease and the slowing of the aging process will lead to a sharp decline in disability,allowing people of advanced age to function as well as they did when they were much younger.In other words,a 90-year-old person could have the same mental and physical capacity as somebody 40 or 50 years old."



What does the new study show？ ______

A. Few people pay attention to the health care reform in the US.
B. Great progress has been made in the US in public security.
C. Americans will live much longer by 2050 than they do now.
D. Fewer Americans suffer from deadly disease now than before.

What probably helps American live much longer？ ______

A. Social security.
B. Biomedical technology.
C. Healthcare reform.
D. New research in health care.

What problem may a longer life expectancy in the US lead to？ ______

A. The aging process will speed up.
B. It adds to the chance of being disabled.
C. The old will have some mental problems.
D. It will increase public costs for the government.

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

A. Life for Senior Citizens in the US
B. The Longer Life Expectancy in the Future
C. The Disadvantage of Longer Life Expectancy
D. What Can Be Done to Support So Many Aged People

Ever wonder how your brain works when making decisions bigger than medium versus spicy sauce, like buying a car or accepting a job offer？ Researchers from the University of Dundee in Scotland conducted a study that clarifies why you may want to have a small bite before making that big decision.
Benjamin Vincent from the University of Dundee's Psychology department and his co-author Jordan Skyrnka tested 50 people two times： once when they followed their normal eating patterns and once when they did not eat anything during the day. Using three different types of rewards （food, money, and song downloads）， the team discovered when presented with the choice of receiving the reward now versus double the award at some point in the future, participants would usually volunteer to wait for 35 days to earn a larger bounty， but when they were hungry, they said they would only wait three days.
"We wanted to know whether being in a state of hunger had a specific effect on how you make decisions only relating to food or if it had broader effects, and this research suggests decision-making gets more present-focused when people are hungry," Vincent said in a story about the study on the university's website. "You would predict that hunger would impact people's preferences relating to food, but it is not yet clear why people get more present-focused for completely unrelated rewards. Hunger is so common that it is important to understand the non-obvious ways in which our preferences and decisions may be affected by it," he said.
In an earlier study of the subject by a team at Cambridge University in England, the researchers noted that serotonin（血清素） plays a major role in the decision-making process. "Since the raw material for making serotonin—an amino acid（氨基酸） called tryptophan（色氨酸） — only comes from diet, levels of the chemical decline between meals," reports a piece in the Telegraph about the study. "This can lead to aggressiveness and impulsiveness," say the team.



How did Benjamin Vincent and Jordan Skyrnka carry out their research？ ______

A. By analyzing reasons.
B. By making comparison.
C. By giving examples.
D. By filling questionnaires.

The underlined word "bounty" in paragraph 2 can be best replaced by ______ .

A. bonus.
B. quantity.
C. income.
D. fortune.

What conclusion can we draw from Vincent' study？ ______

A. It's common to make a wrong decision if you are hungry.
B. Make sure you are not hungry before making a big decision.
C. The more hungry you are, the quicker you will make a decision.
D. Being hungry drives you to make a decision connected with food.

What is the last paragraph mainly about？ ______

A. What should be eaten to make a wise man.
B. How can we get enough serotonin from our diet.
C. What other factors will influence one's decision-making.
D. How does a chemical function in the course of making a decision.

Preparations for the Tokyo Olympics have suffered another challenge after a survey found that 60% of people in Japan want them to be cancelled,less than three months before the Games are scheduled to open.
Japan has extended a state of emergency in Tokyo and several other regions until the end of May as it struggles to control a fast increase in COVID-19 cases caused by new,more catching variants（变异体）with medical staff warning that health services in some areas are on the edge of breaking down.
The Olympics,which were delayed by a year due to the pandemic,are set to open on 23 July,with the International Olympic Committee（IOC）and organizers insisting that measures will be put in place to ensure the safety of athletes and other visitors,as well as a nervous Japanese public.
The survey,conducted between 7 and 9 May by the conservative Yomiuri Shimbun,showed 60% wanted the Games cancelled as opposed to 39% who said they should be held. "Postponement" — an option abandoned by the IOC — was not offered as a choice.
Of those who said the Olympics should go ahead,23% said they should take place without audience.Foreign audience have been banned but a final decision on native attendance will be made in June.
Another poll conducted at the weekend by TBS News found 65% wanted the Games cancelled or postponed again,with 37% voting to give up the event altogether and 28% calling for another delay.A similar poll in April conducted by Kyodo news agency found 70% wanted the Olympics cancelled or postponed.
The IOC's vice president,John Coates,said that while Japanese sentiment about the Games "was a concern"，he could foresee no situation under which the sporting events would not go ahead.



How many Japanese wish the Olympics would not be held in Tokyo according to the survey？ ______

A. 60%.
B. 28%.
C. 37%.
D. 70%.

What should be put into consideration if the Olympics open？ ______

A. The economic crisis.
B. The urban transport.
C. The safety of athletes.
D. The health condition of citizens.

What is some people's attitude towards foreign spectators in Paragraph 5？ ______

A. Welcome.
B. Unfriendly.
C. Cold.
D. Unsupported.

What can we conclude from John Coates' words？ ______

A. The Olympics will be stopped this year.
B. The Olympics will be put off.
C. The Olympics will be held normally.
D. The Olympics will take place in other place.

When my friend suggested going to the op shop（二手商店），instantly I thought "I hope no one I know sees me".It was the same when my cousin commented on my new furniture and Japanese,fine-bone-china bowls and asked where I got them.They were from the local op shop but instead I said "from the antique shop".
Many people in my Greek-Cypriot community would look down on me if I said I shopped at the op shop.They may pity me,consider me poor,a failure.Immigrants sacrificed their families and homes for a better life.Buying a house and having enough money to live comfortably,to educate your children and see them also live comfortably,are a big part of the immigrant dream,But has this dream made us materialistic at the cost of our own planet？
Our love for purchasing the latest trendy clothes or furniture,then donating them when we are tired of them has become normal.I was once like this.But after watching the documentary The True Cost I learned donated clothes that don't get sold are sent to developing nations,many of them ending up in landfills（垃圾填埋地）.In addition,your new dress requires electricity and materials to make.But if you buy a second-hand dress,that's one less dress in a landfill and one less new dress to be made.
A friend introduced me to op shopping only a few years ago.My first item was a dress she gifted me.It was lovely and I loved it.Nobody could tell it was second-hand.This opened me up to purchasing more second-hand high quality branded clothes.Once I visited a friend and was impressed by how she decorated her apartment. "It's all second-hand," she said.I couldn't believe it.The truth is a lot of things sold at the op shop are in new or almost new condition.That's when I made the decision to only buy second-hand things.
Selling second-hand things isn't anything new but what the planet needs is more buyers.There is so much excess （过量） production in the world.So stop feeling ashamed,and let's get shopping.



What kind of feeling is expressed in Paragraph 1？ ______

A. Pride.
B. Embarrassment.
C. Delight.
D. Sympathy.

What are many people in the author's community like？ ______

A. They are probably materialistic.
B. They care about the environment.
C. They think highly of op shopping.
D. They look down upon immigrants.

What was the author encouraged to do after visiting her friend's apartment？ ______

A. Watch the documentary The True Cost.
B. Donate more to local charities.
C. Avoid shopping too much.
D. Stop buying new things.

What's the purpose of the text？ ______

A. To entertain.
B. To advertise.
C. To persuade.
D. To describe.

When you walk with a backpack,do you know how the things inside move from side to side？Now scientists have figured out how to tap into that movement to produce electricity.
Picture a pendulum （摆锤） fixed to a backpack frame and stabilized with springs on either side.The pack's weight is attached to the pendulum,so the pendulum swings side to side as you walk.Then a machine is driven by that swinging movement,and spits out electrical current to charge a battery.
Volunteers carried the pack while walking on a running machine and wore masks to measure the flow of O₂ and CO₂.Walking with the slightly swinging 20-pound load,the device（设备）did not significantly affect the volunteers' metabolic （新陈代谢的） rate compared to when they carried the same weight fixed in place.In fact,the energy-harvesting pack reduced the forces of acceleration they'd feel in a regular pack,which might mean greater comfort for a long hike.And the device did produce a steady trickle（涓流） of electricity.If you up the load to 45 pounds,the swing of the pack could fully charge a smart phone only after 12 hours.The details are in the journal Royal Society Open Science.
The device produces electricity from human movement and has been identified as a workable solution to providing a renewable energy source for portable electronic devices.It is particularly useful for those who work in remote areas,as these people often carry a lot of weight in a backpack for their exploration.
But here's a real conundrum：the energy-harvesting device currently weighs five pounds.The researchers say that's about four pounds too many to be a smart alternative to batteries.So they hope that more research lets them lighten the load,to ensure the pack charges you up without weighing you down.



What does Paragraph 2 mainly talk about？ ______

A. How the device works.
B. What the device looks like.
C. Who the device is designed for.
D. Why scientists designed the device.

Which of the following describes the device？ ______

A. It greatly affected the volunteers metabolic rate.
B. It harvested energy as the volunteers walk.
C. It failed to produce steady electricity.
D. It was useless for a long walk.

What does the underlined word "conundrum" in the last paragraph mean？ ______

A. Problem.
B. Method.
C. Bond.
D. Decision.

What will the researchers try to do next？ ______

A. Increase the charging speed of their device.
B. Find smarter alternatives to batteries.
C. Reduce the weight of their device.
D. Put their device on the market.

Japan is known to have higher than average rates of stomach cancer,Recently,the town of Kaneyama in Yamagata Prefecture decided to get its 6，000 residents （居民） tested.
However,the frozen urine samples（尿样）are not tested in conventional ways.Instead,Professor Masao Miyashita and his team are using them in a trial to determine if specially trained cancer-sniffing dogs can accurately detect the disease.Though the study is still in its early stages,Miyashita is thrilled with the results.He said, "In our research so far,cancer detection dogs have been able to find signs of cancer with an accuracy of nearly 100 percent."
Researchers have known about the animals' superior sensory skills for decades.However,their ability to detect cancer in humans came to light in 1989，after a dog sniffed out early-stage malignant melanoma（恶性黑色素瘤）on a patient's leg in London.Since then,scientists from many countries have conducted studies to test dogs' great skill at identifying cancer chemicals.
While most dogs can be trained for the task,researchers say the best candidates are dogs that are precise,quiet,and perhaps even a little shy.The training process is similar to how dogs are taught to learn any trick — by rewarding them with treats!However,it takes much longer because the dogs have to learn to separate the "cancer scent （气味）" from the thousands of organic compounds（有机化合物） in the human body.Researchers begin by exposing the dogs to urine samples from people with cancer,people with other diseases,and patients with no health issues,Once the dogs are able to accurately identify cancer,they are further trained to detect particular kinds of cancer.
Successful as they may be,experts think dogs are unlikely to replace conventional tests.For one,it takes about seven years and costs as much as ＄45，000 to train a single dog.Klaus Hackner,a researcher and physician who studies dogs detecting cancer in breath samples at Krems University Hospital in Austria,is also not convinced dogs can be relied upon alone.Patients,therefore,have to receive further tests to confirm if they have the disease.



What do we know about the cancer-sniffing dogs mentioned in Paragraph 2？ ______

A. They have done a great job.
B. They are trained in a special way.
C. They can easily learn to distinguish cancer.
D. They can be seen in many Japanese hospitals.

What does the author intend to do in Paragraph 3？ ______

A. Offer readers some advice.
B. Add some background information.
C. Summarize the previous paragraphs.
D. Introduce a new topic for discussion.

What kind of dog is suitable for the cancer-sniffing job？ ______

A. Smart and brave.
B. Active and faithful.
C. Strong and patient.
D. Careful and peaceful.

What is Klaus Hackner's opinion on cancer-sniffing dogs？ ______

A. They should work as a team.
B. They need to receive more training.
C. They can replace doctors in detecting cancer.
D. They should be used together with traditional tests.