Sea urchins(海胆) are small creatures , but what’s really remarkable about them is that they eat anything that happens to float by. They have really sharp teeth they use to rid rocks of algae(海藻)which makes them pretty valuable especially in places like Hawaii where algae are threatening the coral reefs. In the summer of 2019, 500,000 of them were used to deal with the algae.
The problem started when non-native algae were introduced to the ecosystem of Kaneohe Bay in the 1970s. Because they had no enemies, they ended up taking over the bay, according to the National Marine Fisheries Service (NMFS). The algae blocked sunlight from reaching the coral, which in turn affected the local fish because they changed the chemistry of the water.
That’s when the NMFS turned to sea urchins that loved to devour the algae. But they had to grow to the size of a cherry tomato before they could be used. Since 2011, sea urchins have been grown and used to handle the algae problem. Some of the funds are available due to an unfortunate incident. In 2005, a ship was grounded on a shallow reef near Kaneohe Bay. When the ship was removed, 20 acres of reefs have been damaged. When there is environmental damage, the NMFS and other agencies receive funds from the wrongdoers and the funds are used to restore the damage. Some funds were spent on other projects like the sea urchins. The state of Hawaii began to grow the sea urchins. When they are large enough, divers carefully place them on the reef.
Algae isn’t the only thing that threatens the coral reefs. Climate change and the effects of fishing and tourism in the area also endanger the coral reefs. But turning to sea urchins instead of man-made solutions seems like the best way to go.
1. Why are sea urchins regarded as outstanding creatures?| A．They are tiny but have teeth. |
| B．They can keep the ocean clean. |
| C．They can remove harmful algae. |
| D．They grow on coral reefs with algae. |
| A．They helped the coral reefs to survive. |
| B．They spread to every corner of the bay. |
| C．They didn't fit in with the new surroundings. |
| D．They fought against other species to get food. |
| A．Eat | B．Block |
| C．Attack | D．Attract |
| A．Banning fishing and tourism. | B．Relying on humans’ solutions. |
| C．Employing divers to handle algae. | D．Letting nature take care of nature. |
相似题推荐
【推荐1】When scientists go to a forest to study monkeys and their habits and behaviors, how do they know who’s who?
In the past, scientists had to make marks on each of the animals to distinguish them. But in the future, they may have a much easier way to tell them apart thanks to facial recognition technology.
A research team from China’s Northwest University is using facial recognition technology to identify thousands of snub-nosed monkeys that live on Qinling Mountain in Shaanxi province.
Similar to human facial recognition, the technology that is used to identify monkeys uses their facial features to create a database that includes every monkey, Xinhua reported. “When the system is fully developed, we can connect it with cameras set up in the mountains. The system will automatically recognize the monkeys, name them and analyze their behavior,” said Zhang He, a member of the research team. “For each snub-nosed monkey, we have 700 to 800 image samples, and the recognition success rate is 94 percent,” Zhang added.
“We used mobile phones and portable cameras with the monkeys in tests at distances ranging from about 3 to 10 meters,” said He Gang, a member of the research team and an associate professor in the College of Life Sciences at Northwest University. “There is no need to interfere with the monkeys. Such a method of sampling is clearly non-invasive.”
Compared to humans, facial recognition technology for monkeys is more complicated because of their hairier faces. The color of their hair causes them to blend into their environment. These factors make it harder for computers to identify them.
“Monkeys do not cooperate with researchers in the same way humans do. It is difficult to take high-quality pictures and videos of them, which are needed to improve the system,” said Li Baoguo, leader of the research team.
Currently, there are about 4,000 snub-nosed monkeys living on Qinling Mountain. The team’s goal is to successfully identify every monkey that lives there.
1. What problem do scientists face while studying monkeys according to the text?| A．How to mark them. | B．How to tell them apart. |
| C．How to understand their behavior. | D．How to observe them clearly |
| A．It is now widely adopted in China. |
| B．It works better than human facial recognition. |
| C．It will use monkeys’ behavior to create a database. |
| D．It can help scientists study monkeys without disturbing them. |
a. Image samples. b. Hairy faces. c. Hair color. d. The environment.
| A．ab | B．ac | C．bc | D．bd |
| A．To introduce a new way to identify monkeys. |
| B．To show the importance of studying monkeys. |
| C．To compare different ways to identify monkeys. |
| D．To explain difficulties in developing a new system. |
【推荐2】A family is nice to have. Some of us have lots of relatives. Others have just one or two. And some of us live in adopted families. What about wild animals? Some are loners, but many species live permanently in families, just as we do.
When I studied African wild dogs, I saw that each pack consists mainly of grown brothers and their father and uncles. Usually, one unrelated female lives with them. If a dog gets lost, it makes its special “hogcall”, and the others answer. Warthogs also live in families. A common group would be an old mother, her grown daughters, and these daughters' grown daughters with their babies. If these warthogs become separated, they look for one another.
But some other plant eaters seem to have almost no family ties. For example, caribou live in huge herds of hundreds or even thousands of animals. Except for each mother and her baby, these animals do not appear to remember one another. If some of them get lost, the others do not seem to miss them.
An animal can be in great danger if it has no family to help fight off predators (捕食性动物). I once saw a rooster try to defend his chicks from a snake. He was killed by the snake. The wildebeest, which lives in a herd, is on its own when predators strike. That is because a wildebeest herd, like a caribou herd, is just a crowd of unrelated animals that do not know or care about one another. Many times I saw wildebeest mothers standing alone, trying to protect their babies from wild dogs. But in the end, each mother had to flee for her own life.
However, a big family is sometimes a nuisance (麻烦事). The little dikdik is a tiny antelope that lives in Africa. It has a diet of rare plants and is limited to a small home range. The dikdik would not find enough to eat if there were too many relatives around. The female leopard, too, lives alone all her life, except while she's raising cubs (幼崽). She usually hunts small animals, which are just big enough to feed her and her cubs, but nobody else.
1. What would an African wild dog do if it couldn't find its way home?| A．It would let out a special call. | B．It would listen to the father's call. |
| C．It would leave some marks on the ground. | D．It would follow the family's unique smell. |
| A．Females form close circles. | B．The oldest one is usually the leader. |
| C．Young ones are independent of their parents. | D．Family members fight off predators on their own. |
| A．Her babies run away from her. | B．Predators are scared away. |
| C．She gets herself killed. | D．Her efforts are in vain. |
| A．They are loners. | B．They are big eaters. |
| C．They are peacelovers. | D．They do much for their cubs. |
【推荐3】Capybaras (水豚) are group animals, so they do not like being alone. In fact, leaving a capybara alone is not only uncomfortable for the animal, but it can be harmful to their physical health, as well as their mental happiness. Capybaras love to talk to each other throughout the day. Groups of capybaras spend their days sun bathing along the edge of rivers, where they enjoy swimming together in the water. They spend half of their lives in the water.
Since they spend so much time around water, it makes sense that capybaras would come into contact with different kinds of other animals who stop in for a drink. Capybaras are gentle and peaceful river animals who enjoy a short sleep along the water’s edge — and often do so with other animal species as well. You can find pictures all over the Internet of these lovely animals lying beside turtles, birds, ducks, rats, and even monkeys as they enjoy a nap by the water.
Capybaras are also known to be excellent and friendly taxis in the animal world. Birds and monkeys commonly stand on the back of a capybara for a ride as capybaras search for grass to eat. Sometimes capybaras even serve as boats for other animals, letting them sit on their heads as they swim through the water.
However, if you see a capybara lying on its side with a yellow-headed caracara (长腿秃鹰) on its body, don’t panic just yet. Most likely the copybara is enjoying a nice spa day. Birds often make friends with capybaras and provide a natural cleaning service, picking off insects that live in the capybara’s fur. It’s a relationship that benefits each other, since the yellow-headed caracara also gets to enjoy eating those tasty insects. Yet, such lovely capybaras are not free of human influences and even face extinction now.
1. What does the first paragraph mainly tell us about capybaras?| A．Their life habits. | B．Their survival skills. |
| C．Their appearance. | D．Their risks in health. |
| A．They search for food for birds and monkeys. |
| B．They carry their food by riding on another animal. |
| C．They allow other animals to stay on their backs or heads. |
| D．They guide other animals to swim through the water as a driver. |
| A．The caracara won’t attack you. |
| B．The capybara won’t suffer any injury. |
| C．The caracara may just take a short break. |
| D．The capybara may be providing its cleaning service. |
| A．Calls for protection. | B．Habits of caracaras. |
| C．Benefits of extinction. | D．Threats from capybaras. |
【推荐1】It may help you to know that there is no such thing as a perfect speech. At some point in every speech, every speaker says something that is not understood exactly as he has planned. Fortunately, such moments are usually not obvious to the listeners, why? Because the listeners do not know what the speaker plans to say, they hear only what the speaker does say. If you lose your place for a moment, wrongly change the order of a couple of sentences, or forget to pause at a certain point, no one will be any the wiser. When such moments occur, don’t worry about them. Just continue as if nothing happened.
Even if you do make an obvious mistake during a speech, that doesn’t really matter. If you have ever listened to Martin Luther King’s famous speech — “I have a dream”, you may notice that he stumbles over his words twice during the speech. Most likely, however, you don’t remember. Why? Because you were fixing your attention on his message rather than on his way of speech-making. People care a lot about making mistakes in a speech because they regard speech-making as a kind of performance rather than as an act of communication. They feel the listeners are like judges in an ice-skating competition. But, in fact, the listeners are not looking for a perfect performance. They are looking for a well-thought-out speech that expresses the speaker’s ideas clearly and directly. Sometimes a mistake or two can actually increase a speaker’s attractiveness by making him more human.
As you work on your speech, don’t worry about being perfect. Once you free your mind of this, you will find it much easier to give your speech freely.
1. You don’t remember obvious mistakes in a speech because ________.| A．you find the way of speech-making more important |
| B．you don’t fully understand the speech |
| C．you attention is on the content |
| D．you don’t know what the speaker plans to say |
| A．Walks wrongly. | B．Makes an error with. |
| C．Misunderstands. | D．Forgets. |
| A．one or two mistakes in a speech may not be bad |
| B．giving a speech is like giving a performance |
| C．the listeners should pay more attention to how a speech is made |
| D．the more mistake a speaker makes, the more attractive he will be |
| A．If you are careful enough, you can make a perfect speech. |
| B．Listeners are not judges and they pay more attention to the message. |
| C．Speech-making is a kind of performance. |
| D．Martin Luther King is not a good speaker. |
【推荐2】Winners of 2019 Gloria Barron Prize
Gloria Barron Prize for Young Heroes is an award that celebrates young people from across North America who have had a positive impact on people, their communities and the environment, Each year, the Prize honors 25 young leaders from ages 8 to 18. Fifteen top winners each receive S 10,000 to support their service work or higher education. Here are some of the teenagers who have won the prize this year.
Charlie Abrams, 15, and Jeremy Clark, 14, of Oregon, who co-founded Affected Generation, a youth-led nonprofit working to fight climate change, help implement (实施) effective climate policy, and create environmental films.
Anna Du, 13, of Massachusetts, who invented a Remotely Operated Vehicle (ROV) that detects micro-plastics on the ocean floor. She also wrote a children’s book, Microplastics and Me, and has raised more than $7,000 to distribute the book free to libraries in high-need communities.
Garyk Brixi, 18, of Maryland, who developed better life-saving relief food for starving children in developing countries. He is now teaming with an NGO (非政府组织) to begin producing his food in Malawi.
Katherine McPhie, 17, and Milan Narula, 16, of California, who co-founded Open Sesame Coding for Kids and have taught computer coding skills to more than 100 children living in homeless and domestic violence shelters.
Will, 14, and Matthew Gladstone, 11, of Massachusetts, who co-founded the blue Feet Foundation to help save the blue-footed booby (鲣鸟). They have sold more than 10, 000 pairs of bright blue socks to raise more than $80,000 to fund research to study the bird’s decline in the Galapagos Islands.
1. What words can best describe the winners of Gloria Barron Prize?| A．Clever and socially active. | B．Independent and adventurous. |
| C．Cooperative and open-minded. | D．Inspiring and socially responsible. |
| A．Three. | B．Four. |
| C．Five. | D．Six. |
| A．Anna Du made a difference with her writing abilitie. |
| B．Charlie Abrams has created many environmental films. |
| C．Milan Narula is teaching computer coding skills at a school. |
| D．Will is studying the booby’s decrease in the Galapagos Islands. |
【推荐3】Beethoven remains one of the most admired and prolific composers throughout the history. He completed 722 musical works. Unluckily, the master died while still working on his 10th Symphony (交响曲). Now, a team of musicians and scientists have used artificial intelligence (AI) to complete the artist’s final composition.
Dr. Matthias first came up with the idea to complete the composition in 2019. He thought it was an appropriate way to celebrate Beethoven’s 250th birthday in December 2020. He began by recruiting an international team of music experts to help him with the giant task. They included music composer Walter and Dr. Ahmed, the creator of an innovative AI technology for the art market.
Ahmed and his colleagues started the process by familiarizing the AI software initially with a broad range of classical music, and then, narrowed it to just Beethoven’s work. Meanwhile, Walter and his group tried to interpret the rough drafts and the handful of notes that detailed Beethoven’s plans for the 10th Symphony.
The team then began the slow and careful task of feeding the AI software musical notes from the unfinished composition. To stay true to Beethoven’s original composition, Ahmed’s team sent Walter hundreds of AI-generated musical note variations every evening. Walter would listen to them and then select the one that he thought was closest to what the artist would have written. The AI team would add the music and rerun the software to generate the next suggestions. And piece by piece, the team was able to complete Beethoven’s 10th Symphony!
The composition was firstly released on October 9, 2021. Not surprisingly, it caused some controversy (争议). Critics believe technology should not be used to replicate the human creative process. Ahmed and his team agree with their opinions and say their AI software is not out to replace humans—it is just a tool to help artists to express themselves in new ways.
1. What is the writer’s main purpose of writing the first paragraph?| A．To voice his greatest respect for Beethoven. |
| B．To compare traditional music with AI music. |
| C．To introduce an innovative method to create music. |
| D．To present the team of music experts’hard work. |
| A．Challenging. | B．Steady. | C．Simple. | D．Boring. |
| A．Question. | B．Suspend. | C．Polish. | D．Copy. |
| A．Beethoven’s 10 Symphonies Is Eventually Staged |
| B．A Team of Experts Conduct a Mission Impossible |
| C．AI Helps Complete Beethoven’s Unfinished Symphony |
| D．A Controversial Way Successfully Interprets Beethoven’s Music |
【推荐1】What’s On?
Electric Underground
7.30pm－1.00am Free at the Cyclops Theatre
Do you know who’s playing in your area? We’re bringing you an exciting evening of live rock and pop music from the best local bands. Are you interested in becoming a musician and getting a recording contract(合同)? If so, come early to the talk at 7.30pm by Jules Skye, a successful record producer. He’s going to talk about how you can find the right person to produce your music.
Gee Whizz
8.30pm-10.30pm Comedy at Kaleidoscope
Come and see Gee Whizz perform. He’s the funniest stand-up comedian on the comedy scene. This joyful show will please everyone, from the youngest to the oldest. Gee Whizz really knows how to make you laugh! Our bar is open from 7.00pm for drinks and snacks(快餐).
Simon’s Workshop
5.00pm-7.30pm Wednesdays at Victoria Stage
This is a good chance for anyone who wants to learn how to do comedy. The workshop looks at every kind of comedy, and practices many different ways of making people laugh. Simon is a comedian and actor who has 10 years’ experience of teaching comedy. His workshops are exciting and fun. An evening with Simon will give you the confidence to be funny.
Charlotte Stone
8.00pm-11.00pm Pizza World
Fine food with beautiful jazz music; this is a great evening out. Charlotte Stone will perform songs from her new best-selling CD, with James Pickering on the piano. The menu is Italian, with excellent meat and fresh fish, pizzas and pasta(面食). Book early to get a table. Our bar is open all day, and serves cocktails, coffee, beer, and white wine.
1. Who can help you if you want to have your music produced?| A．Jules Skye. | B．Gee Whizz. |
| C．Charlotte Stone. | D．James Pickering. |
| A．The Cyclops Theatre | B．Kaleidoscope |
| C．Victoria Stage | D．Pizza World |
| A．5.00pm-7.30pm. | B．7.30pm－1.00am. |
| C．8.00pm-11.00pm. | D．8.30pm-10.30pm. |
【推荐2】Superheroes have taken over cinemas for the past 10 years. Superman, Thor, Iron Man, the Black Panther and many more have featured in film series with serious and complex storylines about the end of the universe. However, the makers of Shazam, which came out in China on April 5, have a different take on the superhero movie.
“It’s just a light, funny … action comedy about a boy in a superman’s body,” wrote Owen Gleiberman in his review for Variety magazine.
Billy Batson, the film’s main character, is a 14-year-old who’s spent his life going in and out of foster homes (寄养家庭). One day, on the way to another home, Billy escapes to the subway and meets a wizard (巫师), who gives him magical powers. Whenever Billy says the magic word – “Shazam” – he changes into an adult-sized man with superhuman powers. These new powers include wisdom, strength, stamina, courage and speed. He can also fly.
But how does Billy use his godlike new superpowers? With the help of his new foster brother, Freddie Freeman, Billy tests his strength like any teenager would do – by breaking the rules. He smashes (砸碎) open a soda machine to get free sodas, tricks his teachers, and even buys beer.
While the film is fun and silly, it also has emotional weight. A major part of the story centers on Billy’s search for his real mother. And later, when he faces the villainous Dr Thaddeus Sivana, a former misfit (不合群的人) kid himself, Billy realizes that his new powers can’t fix every problem. He also learns that he has something precious to protect – his new family.
“With strong messages about families of all shapes and sizes and the importance of supporting and nurturing young people, Shazam really feels like the movie we need right now,” wrote Rosie Fletcher at the website Den of Geek.
1. How is Shazam different from other superhero movies?| A．It has a complex, serious storyline. |
| B．It is about the end of the universe. |
| C．It has a light and funny atmosphere. |
| D．It has several important characters. |
| A．He was born with magical powers. |
| B．He has no idea who his real mother is. |
| C．He enjoys his time with his foster family. |
| D．He lives with a wizard near the subway. |
| A．He fails to find his real mother in the end. |
| B．He loves playing tricks with his magic powers. |
| C．He teaches Dr Thaddeus Sivana to be a good person. |
| D．He realizes what his new family means to him. |
| A．Tips for a good superhero |
| B．Wizards live among us |
| C．How to watch Shazam |
| D．Super fun superhero |
【推荐3】Lake Tekapo lies in the center of the South Island in an area known as the Mackenzie Basin in New Zealand. Tekapo Tourism provides one of the most comprehensive accommodation (住宿) listings in the region. All accommodation providers in Tekapo are listed as follows.
• The Chalet Boutique Motel
It’s only a short distance from the Church of the Good Shepherd. You’ll find the Chalet Boutique Motel very close to the shores of Lake Tekapo.
At the Chalet Boutique Motel you have the choice of six self-contained (独立的) apartments varying in size from 2-bedroom apartments to studio apartments (单间公寓). Some offer excellent views of the lake and mountains.
Address: Pioneer Drive, PO Box 2, Lake Tekapo
• Tekapo B2 Apartment
Tekapo B2 apartment is a self-contained, one-bedroom, upstairs apartment with views overlooking Lake Tekapo. It’s only a short walk from the town center. The bedroom is suitable for two people. A double sofa bed is available for a third person or child.
Address: 2 Murray Place, Lake Tekapo
• Mt John Historic Homestead
Built in 1911，the Mount John Homestead has recently been renovated (整修). An original collection of art by a local artist and thousands of local photos are displayed throughout the rooms.
The yard is also available for special occasions such as weddings, family reunions or small parties. A minimum (最少的) booking of 2 nights is required.
Address: State Highway 8，PO Box 91，Lake Tekapo
1. If Lily wants to take a walk along the shores of Lake Tekapo, she’d better stay in .| A．the Church of the Good Shepherd | B．the Chalet Boutique Motel |
| C．Tekapo B2 Apartment | D．Mt John Historic Homestead |
| A．Both have a long history. | B．Both have recently been renovated. |
| C．Both have local photos in the rooms. | D．Both have rooms with a lake view. |
| A．It has studio apartments. | B．It is near the town center. |
| C．It can hold a wedding. | D．It is the cheapest of the three. |
I have listened to music all my life. When I was twelve years old, the Beatles came to America and my whole world opened up. Maybe young people today cannot understand the influence of the Beatles when they exploded across America. Their influence changed the way we dressed, looked, acted and spoke... even our culture. The Beatles arrived in America from the UK just under three months after the assassination(暗杀) of President John Kennedy, which had put America into a great depression. And the freshness and lively spirit of the Beatles was exactly what the country needed to refresh itself.
Music links the heart of the hearer with that of the composer. This means that it mixes the spirit of the composer with your spirit when you listen to it. And the music can take your spirit out of your body and transport you into another world. Music has a great way of touching people. Music can make you laugh, cry or shout. It's also a great source of inspiration.
Try this one day and notice what happens: make yourself a cup of tea, sit on your sofa and play one of your favorite songs. Close your eyes, and soon you'll find yourself creating vivid mental images—matching the music that you are listening to.
1. Music has magical power because it ________.
| A．is a kind of language |
| B．can be played much louder than words |
| C．receives a personal radio signal |
| D．can influence a person's spirit |
| A．were the biggest band in American history |
| B．are not accepted by modern American people |
| C．appeared at a special time in American politics |
| D．represented the roots of American culture |
| A．feeling very refreshed |
| B．having emotional changes |
| C．painting some vivid pictures |
| D．feeling inspired by the composer |
| A．has been influenced by the Beatles |
| B．enjoys drinking tea in his spare time |
| C．admires President John Kennedy very much |
| D．likes to match his own feeling with that of the composer |
【推荐2】We are the CEOs. We are the head designers. We are the top engineers. We are the senior creators. We are the inventors. We are the only maker of our own happiness.
However, we still have learned that people’s views on happiness often change with many outside things. Some people smile happily beside their new cars and homes. Students feel excited when they get better grades. Babies laugh loudly when they get new toys. Maybe true happiness has been lost in these things.
How could we have allowed ourselves to be cheated for so long? Something outside may give us happiness, but what directs us to real happiness is inner (内在的) spirit.
Our spirit is so easily broken, yet it is the single strongest thing we own. Why do people with terrible diseases still smile? Why do those with a broken heart still find joy? The inner spirit is powerful, and it is the only thing on earth that can be broken into pieces but can perfectly mend itself with time. Think about those who suffer a lot but still feel happy. Their inner spirit is very strong.
Our inner spirit will be the greatest gift that we give ourselves. It is our compass (指南针) to happiness, but we are the tour guides.
1. What is the author’s view about happiness?| A．It can be bought from others. | B．It has been lost. |
| C．We create it ourselves. | D．It belongs to successful persons. |
| A．Babies want to buy more toys. |
| B．People like smiling beside their new cars. |
| C．Students feel happy after getting good grades. |
| D．People’s views on happiness change with outside things. |
| A．A compass. | B．People’s inner spirit. |
| C．Other people’s views. | D．Things people can buy. |
| A．To stress the power of inner spirit. |
| B．To introduce the direction of happiness. |
| C．To explain the importance of happiness. |
| D．To tell readers the meaning of the joy. |
【推荐3】There are so many different methods claiming to predict marathon performance. But these are not always very accurate because predicting marathon performance is difficult. However, in our new study, we found it's possible to calculate a critical speed that we can use to predict a runner's marathon time with a good degree of accuracy.
Many things determine how fast you can run a marathon, your physical quality plays a huge role in your performance. For example, excellent marathon runners tend to be slim with long limbs. Fast marathon runners also tend to have a higher maximum rate of oxygen use (vo2 max) and can operate at a high percentage of this maximum for a long time without developing tiredness. The right shoes can make running more economical in terms of how much energy you use. And of course, choosing a flat course with ideal weather conditions can help too.
Endurance (耐久力) running is essentially determined by the fastest speed you can sustain for a given distance. or how long you can run at a given speed. This suggests there is a critical speed which, in theory, we can sustain for quite a long time. It is quite possible that the critical speed is useful for predicting endurance performance.
By analyzing training data from 25,000 athletes, we found we could estimate their critical speeds and predict their marathon performance with 92% accuracy.
We also found that, on average, runners ran the marathon at speeds around 85% of their critical speeds. Faster athletes ran their marathons at close to 93% of their critical speeds, but slower runners did so at 79% of their critical speeds. This means that using training data to estimate your critical speed, certain fitness apps on your smart watch or phone may soon be able to predict your finish time at an even higher degree of accuracy, as well as providing real-time advice about how best to pace your race.
1. What does Paragraph 2 mainly talk about?| A．Differences between excellent runners and average runners |
| B．Conditions to consider before running a marathon |
| C．Characters of successful marathon runners. |
| D．Factors affecting runners' performance. |
| A．By listing key data | B．By telling personal stories |
| C．By quoting famous runners | D．By explaining causes and effects |
| A．Different marathon runners always run at different speeds. |
| B．Marathon runners will run better with the help of some apps. |
| C．Critical speeds for runners given by fitness apps are useful. |
| D．It'll be easy to predict runners' performance with some app |
| A．A standard critical speed for marathon runners. |
| B．The inspiration gained from a marathon. |
| C．A way to predict marathon runners' performance. |
| D．The value of hard and scientific training. |
