选择知识点

Race walking shares many fitness benefits with running,research show,while most likely contributing to fewer injuries.It does,however,have its own problem.
Race walkers 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 sport's rules require that a race walkers 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 calculations race walkers moving at a pace of six miles per hour would bum about 800 calories（卡路里）per hour,which is approximately twice as many as they would bum walking,although fewer than running,which would probably bum 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 sports 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 long distances.
B. They are qualified for the marathon.
C. They have to follow special rules.
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. It's 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

There's a battle storming in the streets of America.Anyone who regularly rides a bicycle knows all about this.Some motorists shout at two-wheeled travelers,who slow traffic.A few will do even worse.
The New York Times reports that incidents of aggression toward bicycle riders appear to be growing.Even though actually every state allows bicyclists the same rights as motorists to use the streets,many drivers still refuse to accept this.They view themselves as Kings of the Road-an impression that has been strongly built by the transportation planning profession,which has designed our cities as if people didn't exist outside of their cars.
But a big new idea to settle this conflict and improve life in the streets for everyone is now taking root among community activists,urban planners and traffic engineers.
"Too many of our streets are designed only for speeding cars.They're unsafe for people on foot or bike.Now,in communities across the country,a movement is growing to complete the streets.States,cities and towns are asking their planners,engineers and designers to build road networks that welcome all citizens," declares the website of a new organization promoting this idea,"Complete the Streets"，the best idea to hit our communities since pizza,or even the bicycle itself.
My home of Minneapolis is one of the biking capitals of America.But it hasn't always been that way.When I moved here many years ago,I was shocked at the strong hostility directed toward me whenever I dared ride my bike down the street.Drivers would suddenly turn in my direction,and then laugh as they nearly knocked me onto the ground.
As the amount of bikes on Minneapolis streets has grown,people have become much more comfortable sharing the road with two-wheelers.Indeed,I get the impression that most motorists now envy rather than hate me,and can't wait to get home where they can jump on their own bikes.This will happen everywhere as more and more Americans discover biking as a great way to get around,save money,lose weight,protect the planet and have fun.



Who cause the traffic problem according to the motorists？ ______

A. Bicycle riders.
B. Urban planners.
C. Traffic engineers.
D. Community activists.

The problem of the battle in the streets is most probably rooted in ______ .

A. weight losing
B. city planning
C. money saving
D. global warming

What is the movement "Complete the Streets" aimed at？ ______

A. Improving health conditions.
B. Promoting walking and bicycling.
C. Building more road networks.
D. Assessing the impact of the conflict.

What is the purpose of this text？ ______

A. To present a problem.
B. To praise the bicyclists.
C. To describe a change.
D. To blame the car riders.

Microplastics,the kind of current working definition,are plastic particles（颗粒）less than five millimeters.So people commonly think the microplastic to be something like a grain of rice or a sesame seed.Actually,most of the microplastics that people are interacting with are quite a bit smaller than the sesame seed size,so it always shocks people when they know about the number of microplastics because they can hardly see a lot of these things,at least with the naked eye.
Kieran Cox,a PhD candidate in marine（海洋的）biology at the University of Victoria,is one of the authors of the study,which is in the journal Environmental Science &.Technology.For their study,Cox and his team pulled together past scientific literature that calculated the number of microplastics in things we commonly consume,such as in tap and bottled water,sugars,seafood-even in the air that we breathe.This analysis helped them figure out the baseline amount of microplastics that people are consuming every year.They couldn't include common foods like beef,vegetables and dairy in their analysis because the data on them doesn't exist yet.In fact,their study could account for only l5 percent of people's caloric in-take.Even missing the majority of what people swallow,the research revealed that-at the very least-humans appear to consume somewhere between 74，000 and 121，000 microplastics every year.That number goes up for people drinking bottled water rather than tap water.
Now,is all the plastic safe to take in？Scientists don't know yet.This is like the first estimate of the dose which means an amount of a medicine that is taken once.So the amount is a very important factor to think about,but it is very difficult to estimate because it is what we don't know.



What do we know about the microplastic？ ______

A. It's much bigger than a grain of rice.
B. It's barely seen without an instrument.
C. It can be a kind of fish feed.
D. It's harmless to humans.

What is the second paragraph mainly about？ ______

A. The study of microplastics people consume.
B. The analysis of past scientific literature.
C. The amount of microplastics in food.
D. The study of marine biology.

Which aspect should scientists focus on in further study according to the text？ ______

A. Making plastics safe.
B. The things people swallow.
C. The amount of bottled water.
D. Finding the safe dose of microplastics.

What can we learn about the study？ ______

A. It was about a new material.
B. It was published in a journal.
C. Kieran Cox didn't finish it.
D. Scientists did it by using marine life.

Travel is the only thing that will really make you richer.While it's very valid,there're many times when we are simply unable to travel for certain reasons.However,there's still a great and affordable way to experience new places：books.
Wild
Wild is Cheryl Strayed's beautifully written story of hiking the Pacific Crest Trail for 1，100 miles all by herself.Her journey of self-discovery and facing her painful past is fascinating and will keep you fascinated from the first page up until the last.You will feel like you're hiking alongside strayed the whole time.
On the Road
Jack Kerouac's classic novel in 1957 is a masterpiece from the Beat Generation,which tells the timeless tale of being young,confused,and just getting on the road to try to figure it all out.The book tells the personal developmental story of Sal,who is strongly based on Kerouac himself,leaving New York City and traveling around the country.The book ensures madness,along with colorful characters and heartbreaking moments.
The Caliph's House
This book is written by author Tahir Shah,whose experience of vacationing in Morocco of Africa during his childhood growing up led him to move with his family from London to Morocco,where he learned a lot.His writing is rich and fascinating and tells an incredible story of their time of living there.
The Great Railway Bazaar
Paul Theroux's book narrates his four-month experience in 1973 traveling by train from London to Europe,the Middle East,the Indian subcontinent and Southeast Asia,as well as his return trip on the Trans-Siberian Railway,enriching and improving himself.Theroux explored poverty and ignorance throughout the book,which is often considered as a classic in the travel writing world.



Which book tells of the author's long journey on foot？ ______

A. Wild.
B. On the Road.
C. The Caliph's House.
D. The Great Railway Bazaar.

What is the main content of The Caliph's House？ ______

A. The author's rich writing experience.
B. The story of British children in Africa.
C. The vacation of an African family in London.
D. The author's childhood experience in Morocco.

What are the four books mainly concerned with？ ______

A. Madness and sadness.
B. Travel and self-growth.
C. Poverty and confusion.
D. Childhood and ignorance.

When you hear the beginning of your favorite song from the radio,suddenly your neck is covered in goose bumps （鸡皮疙瘩）.
It's such a thing that a group of scientists call "skin excitement"-a feeling of cold caused not by a drop in temperature or sudden scare,but by the sense of beauty. "Skin excitement" can come from a song,a painting,a moving movie scene,or even a beloved memory-pretty much anything that causes the giving out of pleasure soaked dopamine （多巴胺）in your brain.But it does not come for all of us.
Your favorite music uncovers a lot about your personality,and so does how you respond to that music.Studies suppose that as few as 55 percent of people experience："skin excitement" when listening to music.And if you count yourself among this group,the goose bumps on your skin aren't the only giveaway-scientists can read it in your brain,too.In a new study published in the journal Social Cognitive and Affective Neuroscience,Harvard researchers performed brain scans on 10 students who said they reliably got cold when listening to music,and 10 students who didn't.They found that the cold prone （容易发冷的）brains may really be excited by stronger emotions.
Cold-prone brains are generally more likely to show stronger emotional intelligence than no-cold brains.Cold- prone minds tend to have unusual active imagination,reflect more deeply on their emotions,and appreciate nature and the beauty of music and art to a stronger degree than no-cold brains.
So,what type of music causes the chills？It seems that the type is not so important；participants in the new study reported getting cold from songs of every kind.And any song connected with a strong emotional memory of the listener can produce the most reliable results.For me,that's the song Sailing to Philadelphia by Mark Knopfler,which I listened to as a kid in the car with my dad,on the way to the summer camp.



What can we learn about "skin excitement" in the text？ ______

A. It helps to produce dopamine.
B. It is caused by the pain in the skin.
C. It can be experienced by every music listener.
D. It is the human body's reaction to something nice.

What does the new study by Harvard researchers mainly find？ ______

A. The percentage of music lovers in students.
B. The solutions to the goose bumps on one's skin.
C. The differences between cold prone and no-cold brains.
D. The relationship between one's music preference and personality.

What are people with cold-prone brains like？ ______

A. Beautiful and intelligent.
B. Emotional and dishonest.
C. Imaginative and sensitive.
D. Brave and strong-minded.

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

A. Responses to Music Vary among People
B. A Feeling of Cold Is Caused by Horrible Music
C. Your Favorite Music Reveals Your Personality
D. Favorite Music May Bring Forth Goose Bumps

There's a battle storming in the streets of America.Anyone who regularly rides a bicycle knows all about this.Some motorists shout at two-wheeled travelers,who slow traffic.A few will do even worse.
The New York Times reports that incidents of aggression toward bicycle riders appear to be growing.Even though actually every state allows bicyclists the same rights as motorists to use the streets,many drivers still refuse to accept this.They view themselves as Kings of the Road-an impression that has been strongly built by the transportation planning profession,which has designed our cities as if people didn't exist outside of their cars.
But a big new idea to settle this conflict and improve life in the streets for everyone is now taking root among community activists,urban planners and traffic engineers.
"Too many of our streets are designed only for speeding cars.They are unsafe for people on foot or bike.Now,in communities across the country,a movement is growing to complete the streets.States,cities and towns are asking their planners,engineers and designers to build road networks that welcome all citizens," declares the website of a new organization promoting this idea,"Complete the Streets"，the best idea to hit our communities since pizza,or even the bicycle itself.
My home of Minneapolis is one of the biking capitals of America.But it hasn't always been that way.When I moved here many years ago,I was shocked at the strong hostility directed toward me whenever I dared ride my bike down the street.Drivers would suddenly turn in my direction,and then laugh as they nearly knocked me onto the ground.
As the amount of bikes on Minneapolis streets has grown,people have become much more comfortable sharing the road with two-wheelers.Indeed,I get the impression that most motorists now envy rather than hate me,and can't wait to get home where they can jump on their own bikes.This will happen everywhere as more and more Americans discover biking as a great way to get around,save money,lose weight,protect the planet and have fun.



Who cause the traffic problem according to the motorists？ ______

A. Bicycle riders
B. Urban planners
C. Traffic engineers
D. Community activists

The problem of the battle in the streets is most probably rooted in ______ .

A. weight loser
B. city planning
C. money saving
D. global warming

What is the movement "Complete the Streets" aimed at？ ______

A. Improving health conditions.
B. Promoting walking and bicycling.
C. Building more road networks.
D. Assessing the impact of the conflict.

What is the purpose of this text？ ______

A. To present a problem.
B. To praise the bicyclists.
C. To describe a change.
D. To blame the car riders.

Some people think going to the gym takes time and effort.It often hurts,and it can be very boring.Most weight-related exercises are a combination of sets and reps（几次几组）.In order to see any significant change from any one exercise,it will probably need to be repeated six to eight times,for a minimum of three sets,for about three months.Then there's aerobics（有氧运动）.For some,there's nothing more boring than endless miles pent running on a treadmill（跑步机）.
But what if there is a way to reduce the boredom of exercise while still getting a good workout？Luckily for us,there's virtual reality（VR）.
"In the past,playing video games was a sedentary（久坐不动的）experience," says Jo Stauffer of the VR Health Institute,"but YR changes all of that." Many VR games are played while standing.In order to play properly,the players are forced to move around swinging their arms or using their legs.After an hour of this on a regular enough basis,it's not surprising that many people unexpectedly find themselves a little fitter.There are already a number of virtual reality games which,deliberately or not.result in their player "getting a good sweat on" if played for enough time.For example,there's a music game which forces players to shadowbox（做空拳攻防练习）in order to hit the notes-that's an upper-body workout.
The benefit of VR has been noticed by one company.They want to take the whole experience into the gym.They are making a resistance machine（阻力试验机），designed to be used in combination with a VR headset（耳机）.Players challenge a virtual competitor in a series of games,which results in a 30-minute full-body workout.However,the cost of the equipment is expensive and there are safety concerns to be worked out,says J.P.Gowner from the consultancy Forrester.
Although it's early days,for those of us who struggle to overcome the boredom of exercise,a new solution could be coming.And a world where a person can exercise and have fun at the same time might be something that many people would want-virtual or not.So don't give up exercising.



What conclusion can we draw from the first paragraph？ ______

A. Most weight-related exercises nearly have no effect.
B. Some people think exercising in the gym is difficult and tiring.
C. Running on a treadmill won't bring significant change.
D. You'd better not go to the gym because of the risk of injury.

Compared with video games,VR games ______ .

A. bring more fun to players
B. take people less free time
C. are more likely to bring players health benefits
D. are more popular with people nowadays

What can we know about the resistance machine？ ______

A. It has been widely used in the gym.
B. There are some disadvantages of it.
C. J.P.Gownder highly recommends it.
D. When using it,people need to have a partner.

Which is the best title for the passage？ ______

A. Virtual Exercise in the Gym
B. Keep Going to the Gym
C. The Boredom of Exercise
D. The Popularity of VR Games

The scientists who re-engineered the plastic-eating enzyme（酶）PETase have now created a new enzyme called "cocktail" ，which can digest plastic up to six times faster.
PETase breaks down PET back into its building blocks,creating an opportunity to recycle plastic and reduce plastic pollution.PET is the most common thermoplastic（热塑性塑料）used to make single-use drinks bottles,which takes hundreds of years to break down in the environment,but PETase can shorten this time to days.The initial discovery set up the prospect of a revolution in plastic recycling,creating a potential low-energy solution to tackle plastic waste.
Now,the same trans-Atlantic team have combined PETase and its "partner"，a second enzyme called MHETase,to generate much bigger improvements：simply mixing PETase with MHETase doubled the speed of PET breakdown,and engineering a connection between the two enzymes to create a "super-enzyme"，increased this activity by a further three times.
The team was co-led by the scientists who engineered PETase,Professor John McGeehan and Dr Gregg Beckham.Professor McGeehan said： "Gregg and I were chatting about how PETase attacks the surface of the plastics and MHETase chops things up further,so it seemed natural to see if we could use them together.Our first experiments showed that they did work better together,so we decided to physically link them. It took a great deal of work,but it was worth the effort - we were delighted to see that our new enzyme is up to three times faster than the separate enzymes."
The original PETase enzyme discovery indicated the first hope that a solution to the global plastic pollution problem might be within grasp,though PETase alone is not yet fast enough to handle the tons of PET bottles.Combining it with a second enzyme,and finding together they work even faster,means another leap forward has been taken towards finding a solution to plastic waste.PETase and the new combined MHETase-PETase both work by digesting PET plastic.This allows for plastics to be made and reused endlessly,reducing our reliance on fossil（化石）resources.



What can we learn about "cocktail" from the text？ ______

A. It doubles the breakdown of plastics.
B. It takes hundreds of years to break down.
C. It contributes to breaking down plastic quickly.
D. It deals with the plastic waste three times faster.

What is the second paragraph mainly about？ ______

A. A new study of PET.
B. The breakdown of PET.
C. The discovery of PETase.
D. The functions of PETase.

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

A. Co-leading the trans-Atlantic team.
B. Combining PETase and MHETase.
C. Attacking the surface of the plastics.
D. Talking about conducting experiments.

What can we infer from the text？ ______

A. PET pollution is no longer a difficult problem to deal with.
B. New enzyme is speeding up our reliance on fossil resources.
C. MHETase-PETase makes the world free from plastic pollution.
D. Plastic-eating enzyme "cocktail" promises new hope for plastic waste.

Plastic baby bottles shed microplastics when heated.Should you be worried about its side-effects？We still don't have enough evidence of health risks posed by microplastic consumptions by infants or adults.
"The last thing we want to do is unduly alarm parents," said John Boland,a professor at Trinity College Dublin in Ireland and one of the authors of the Nature Food study.While the health effects of microplastics are still unknown,parents can significantly reduce their infants' exposure by adding some steps to their bottle preparation routine,Boland said.He recommends letting plastic bottles cool completely after sterilization（消毒）in hot water,then washing them out at least three times with water that's been allowed to cool to room temperature after being sterilized by boiling.Researchers here also found that plastic tea kettles,plastic instant noodle cups and plastic food storage containers all released similarly high levels of microplastics when subjected to heat.
As for what those microplastics may be doing in our bodies,the evidence so far is quite limited and unclear.Schwabl,another professor,said that points to a need for more research into microplastics released from plastic food storage containers,especially when they are subjected to higher temperatures.He noted some research has found microplastics can cause inflammation（发炎） in the organs,while other studies show they do not harm,"The threshold at which they cause problems has not been determined for humans," Schwabl said.For now,Schwabl agrees we shouldn't panic.He's avoiding plastic containers in his daily life- "not so much that I am afraid of the ingestion（吸收），but I think thereby I may be contributing to reducing the amount of plastic waste" that makes its way into the environment.
At the moment,there is no need to be afraid,but it is an open question and definitely an unmet need.



What does the underlined word "unduly" mean in paragraph 2？ ______

A. Properly.
B. Extremely.
C. Obviously.
D. Especially.

Which factor counts in the release of microplastics？ ______

A. Temperature.
B. Products.
C. Time.
D. Containers.

What's Schwabl's attitude towards microplastics？ ______

A. Panic.
B. Caring.
C. Indifference.
D. Critical.

How is the passage developed？ ______

A. By providing the examples.
B. By reasoning the readers.
C. By analyzing the figures.
D. By comparing the findings.

Recently Meituan co-published a proposal with a number of business organizations,including the China General Chamber of Commerce and China Cuisine Association,calling on restaurants to stop food waste and help cultivate new eating habits for customers. "Restaurants should innovate means of publicity using official accounts on social media and live-streaming to promote and advocate food-saving actions," the proposal said.
Meituan and the organizations are advocating that merchants offer guidance for consumers,including reminding them during the ordering process about the taste of the ingredients,portion sizes and other information about the dishes,to help them avoid food waste due to misleading information.
Catering（餐饮）associations in more than 18 provinces have also joined the campaign to eliminate food waste.The China Cuisine Association announced that it had teamed up with Eleme,the Alibaba Group Holding-owned food delivery platform,to launch a "half-dish plan"，encouraging restaurants to provide customers with the option to order smaller portions.The Wuhan Catering Association proposed an "N-1" ordering code for restaurants in which a group of 10 diners would only order enough for nine people.More food is only brought to the table if required.
To curb portrayals of food waste on social media platforms,popular Chinese video platforms such as Douyin and Kuaishou have stepped up content reviews of food-related live streams and implemented regulation of online eating shows.Now if users search certain keywords,such as "eating show" or "competitive eaters"，a cautionary message pops up to remind them to cherish food and maintain a reasonable diet.



Why did Meituan start such a proposal？ ______

A. To popularize itself.
B. To save itself.
C. To mislead the public.
D. To prevent food waste.

What can be inferred from the passage？ ______

A. Wuhan Catering Association's proposal was a good practice.
B. half-dish plan,functioned better than "N-l" ordering code.
C. Meituan met with some management challenges.
D. Customers are required to order smaller portions.

Which of the following is true？ ______

A. Meituan releases some misleading food information.
B. More food is welcome when we treat our dear friends.
C. Few organizations realized the importance of food waste.
D. Online eating shows are monitored via media platforms.

How many good means of avoiding food waste are mentioned here？ ______

A. None.
B. Two.
C. Three.
D. Five.