A bird called hermit warbler breeds（繁殖）along the U.S.West Coast. They all kind of look the same and they have a cute little yellow head and a gray body. Typically, birds sing the same one song within one region because the song attracts mates. And different regions can have slightly different dialects of the song. But recently biologists noticed that there are some places that are exceptions to this rule-in some places, there is more than one song in the same place. “So we were curious why that would be the case.” Brett Furnas, a bio-statistician at the California Department of Fish and Wildlife said.
To investigate, Furnas and his team recorded lots of hermit warbler’s songs. In 10 years, they went to 100 different locations throughout the state and all the different potential habitats of the species. The researchers analyzed all the hermit warbler songs they collected and discovered that the hermit warbler doesn’t just break the usual one-song-per-region rule-they positively demolish it, for the researchers found, actually, an amazing 35 different dialects across the state.
But why would the bird repeatedly “alter its song” when any changes could affect its ability to attract a mate? Basically, hermit warblers are very sensitive to fire in the short term, so they will abandon an area temporarily, even if it’s just a low-severity fire that doesn’t destroy the whole stand. And then other hermit warblers singing different dialects move into this area. And then they end up, maybe a few years later, with two or more different dialects in the same place.
Furnas says that such musical diversity might actually work in the hermit warblers’ favor. “They may have greater resiliency（恢复力）to things like climate change. So understanding that helps us to make better conservation decisions to protect biodiversity. But it’s also what makes the outdoors interesting and a beautiful place to be, because even though you might not know it’s a hermit warbler, your experience outdoors is enriched by that diversity.”
1. What is the purpose of Furnas’ research on hermit warbler?| A．To figure out how the bird breeds. |
| B．To study the one-song-per-region rule. |
| C．To find why its songs differ within one region. |
| D．To investigate different habitats of the bird. |
| A．To show the rule is wrong. |
| B．To prove the rule to be true. |
| C．To explain what the rule means. |
| D．To make the rule difficult to understand. |
| A．Because of the food shortage. |
| B．Because of the less-severe wildfire. |
| C．Because of the need to attract a mate. |
| D．Because of the competition for habitats. |
| A．The effect climate change has on birds. |
| B．The importance of biodiversity protection. |
| C．The ways to enrich your outdoor experience. |
| D．The significance of the musical diversity of hermit warbler. |
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【推荐1】Lots of animals play. But the behavior is best known in mammals (哺乳动物) and birds. Now the scientists at London’s Queen Mary University report that bumblebees (大黄蜂) know the same thing. But before this, there were no reports of insects playing.
Dr. Lars Chittka began to wonder if bumblebees played during an earlier test. In that test, Chittka guided bumblebees to move balls into a goal for food. He noticed that some bees were rolling (滚动) balls even when they weren’t given food. He wondered if they were playing.
To test the idea, the scientists at his lab set up a new test. First, they numbered 45 young bumblebees between one and 23 days old. The numbers let them follow bumblebees’ behavior. Then, they set up a clear pathway from the bumblebees’ home to a feeding area. On either side of the open pathway, the researchers placed small colored wooden balls. On one side of the path, the balls couldn’t move. On the other side, the balls could roll around. For three hours a day, over 18 days, the scientists opened the pathway between the home and the feeding area. The bumblebees never had to leave the pathway to find food, but they left anyway. They weren’t interested in the side where the balls didn’t move, but they made lots of visits to the side with the rolling balls.
Catching the balls with their legs, the bees would move their wings to pull on the balls, causing them to roll. The 45 numbered bumblebees did this 910 times during the test. Though some only did it once, others did it a lot. The younger ones liked to spend more time rolling balls while the older ones showed less interest in it. One bee was recorded rolling balls 44 times in a single day. One was seen rolling balls 117 times over the whole test.
The test raises important questions about how the insects’ minds work and whether they have feelings.
1. What did Chittka want to do about bumblebees in the earlier test?| A．Discover if they played. | B．Train them to move balls. |
| C．Make them learn to relax. | D．Find out if they’d share food. |
| A．They named each of them. | B．They let them interested in balls. |
| C．They had all of them go hungry. | D．They marked them one by one. |
| A．They held their attention for longer. | B．They understood simpler numbers. |
| C．They were less active in rolling balls. | D．They helped the young pull on balls. |
| A．Bumblebees Are First Insects Known to Play |
| B．Two Tests Prove Bumblebees Expect to Play |
| C．Bumblebees Are the World’s Smartest Insects |
| D．Scientists Make Bumblebees Work for Them |
【推荐2】A lot of people are afraid of spiders-even the small ones. But a big tarantula (狼蛛) is much more terrible for many. Now, scientists in Sri Lanka have discovered a huge species (物种) of tarantula that's about the size of a person's face.
Although it is very big, is there a real reason to be afraid of one? Maybe. This tarantula has enough poisonous fluid (液体) to kill mice and small birds and snakes-but its bite wouldn't cause the death of most humans.
Tarantula was first seen in 2009, when a villager in Sri Lanka found the body of a male Tarantula and brought it to a Sri Lanka research organization.
An examination of the body proved that it was a type of tarantula scientists hadn't seen before. So the scientists carefully looked through the Sri Lankan forests to try to find more of the spiders.
It's still too early to know whether this species is in danger. But researchers fear that the Tarantulas' natural habitat (栖息地) is slowly being destroyed.
“They prefer old trees, but due to the widespread removal of trees, the number has dropped,” the scientists said in an interview.
Tarantulas have eight legs and two body parts. They are different from insects, which have only six legs but three body parts. Tarantulas have hairy bodies and are usually larger than other types of spiders. Some species of tarantulas can live up to 25 years.
While Tarantula is very big, the largest one is the Goliath bird-eater. Found in the rainforests of South America, its legs can be up to 10 inches long. But don't worry if you ever see one. Its poisonous fluid isn't really dangerous to humans.
1. Which of the following is most likely to survive a bite from tarantula?| A．A small bird. | B．A little child. | C．A small snake. | D．A small frog. |
| A．They have too many natural enemies. | B．Some people are killing them illegally. |
| C．More and more forests are disappearing. | D．The global climate has changed. |
| A．To inform the readers of a huge species of Tarantula. |
| B．To entertain the readers with a discovery. |
| C．To educate people to protect the environment. |
| D．To remind people to keep away from spiders. |
【推荐3】According to new studies, many birds in the Amazon rainforest have become smaller as temperatures have increased. The difference hasn’t been obvious, but it has been significant enough that some scientists have suggested it’s a universal response to climate change.
But new research finds that the body size reductions aren’t happening across the board with some large-brained birds having much less significant changes.
For the study, researchers studied some data on about 70,000 birds that had died when they crashed into buildings in Chicago from 1978 to 2016. They added data on brain volume and lifespan (寿命) for 49 of the 52 species of migratory birds (候鸟) in the original study.
They found that birds with very large brains had reductions in overall body size that were about one-third of the reductions noted in birds with smaller brains. They thought that in birds, the species with big brains are the ones that build tools, manage to survive in tough environments, live longer, invest more time and energy into raising babies, and end up surviving better in the wild.
Researchers aren’t certain exactly how warmer temperatures might lead to decreasing body size in birds, but they are considering two possible explanations, which could even be happening at the same time. First, natural selection might be favoring birds that can dissipate heat better. This is because smaller birds have higher ratios (比例) of surface area to volume, so being small can help birds stay cool. Second, warmer summers might have less food available for birds at the time when they are feeding their babies. In that case, birds might be getting smaller because of decreased food over the years.
The findings don’t suggest that climate change is having zero impact on bigger-brained birds, but researchers believe these findings can inform us of climate change and help set conservation priorities.
1. How does climate change affect birds?| A．Their body size shrinks. | B．Their lifespan becomes shorter. |
| C．Their body temperature rises. | D．Their habit changes quicker. |
| A．By studying the bird death rate. | B．By observing the birds in nature. |
| C．By analyzing previous information. | D．By comparing different bird species. |
| A．use | B．hold | C．absorb | D．lose |
| A．Birds’ Body Sizes Vary | B．Brain Size Matters for Birds |
| C．Bird Brain Develops Sharply | D．Temperature Rises Globally |
【推荐1】Wikipedia was founded as a branch of Nupedia, a now-abandoned project to produce a free encyclopedia (百科全书). Nupedia required highly qualified contributors, but the writing of articles was slow. During 2000, Jimmy Wales, founder of Nupedia, and Larry Sanger, whom Wales had employed to work on the project, discussed ways of supplementing (补充) Nupedia with a more open project. Multiple sources are suggested for the idea that a wiki might allow members of the public to contribute material, and Nupedia’s first wiki went online on January 10.
There was considerable resistance on the part of Nupedia’s editors and reviewers to the idea of associating Nupedia with a Web site in the wiki format (格式), so the new project was given the name “Wikipedia” and launched on its own domain (域名), wikipedia.com, on January 15. The domain was eventually changed to the present wikipedia.org when the not-for-profit Wikimedia Foundation was launched as its new parent organization. In March 2007, the word wiki became a newly-recognized English word.
In May 2001, a wave of non-English Wikipedias was launched — in Catalan, Chinese, Dutch, Esperanto, French, German, Hebrew, Italian, Japanese, Portuguese, Russian, Spanish, and Swedish. These were soon joined by Arabic and Hungarian. In September, Polish was added. At the end of the year, Afrikaans, Norwegian, and Serbocroatian versions were announced.
Anyone with Web access can edit Wikipedia, and this openness encourages inclusion of a great amount of content. About 75,000 editors — from expert scholars to casual readers — regularly edit Wikipedia, and these experienced editors often help to create a consistent style throughout the encyclopedia.
Editors are able to watch pages and techies (科技人员) can write editing programs to keep track of or correct bad edits. Where there’re disagreements on how to present facts, editors work together to arrive at an article that fairly represents current expert opinion on the subject. Although the Wikimedia Foundation owns the site, it’s largely uninvolved in writing and daily operations.
1. Jimmy Wales wanted a more open project because ______.| A．he wanted to found Wikipedia | B．Nupedia had its own disadvantages |
| C．he earned less money from Nupedia | D．Nupedia had been abandoned |
| A．gained a wide support |
| B．came into being on January 15, 2000 |
| C．made Nupedia better and better known to the public |
| D．weren’t welcomed by all Nupedia’s editors |
| A．Any readers of the Wikipedia. | B．The techies. |
| C．The Wikimedia Foundation. | D．The experienced editors. |
| A．Its owner contributes less to its writing. | B．It appeals to a wider audience. |
| C．Its owner was founded only recently. | D．It was evolved from Nupedia. |
【推荐2】Green exercise is a term used to describe any type of physical exercise that takes place in a natural environment rather than in a health club or gym.
A slightly different approach to green exercise puts more stress on the fresh air, sunshine and involvement with the natural world, rather than the equipment or clothing used during the exercise.
Many consider green exercise helps to reconnect human beings with the natural world. The interaction with nature helps to lower people's blood pressure, refresh their mind, and actually improve their self-esteem.
Not everyone believes that the green exercise is more beneficial than working out in a health club or gym.
| A．A green gym uses as little equipment as possible |
| B．Spirits are also believed to be positively affected |
| C．Opinions on what truly green exercise means differ |
| D．Green exercise includes a range of activities exposed to nature |
| E．So riding a bicycle in the forest can be called a type of green exercise |
| F．It usually doesn't use fitness equipment that is normally found in a gym |
| G．Some point out that many health clubs are built to make full use of natural light |
【推荐3】If you are ever planning to buy a telescope and want to get yourself involved in astronomy, it is always a good idea to know a bit of the sky. Know about a few constellations (星座) so that it will be easier for you to recognize the constellations when you are using your telescope.
It’s a good idea to buy a few astronomy magazines to help you know about the constellations in the sky and also read a few comments on different types of telescopes on the market. This will help you gather all the information that is out there regarding telescopes and what people say about them.
It’s advisable to go in for a pair of binoculars (双筒望远镜) which are very easy to carry and use before you buy your first telescope so that you can get used to locating constellations before your view of the sky is narrowed down. This will also help you know if you really want to get involved in astronomy. Many people buy a costly telescope and then discover that they’re not actually interested in astronomy.
It’s an obvious truth that experience has no replacement, and there certainly is nothing better than using different telescopes before you buy one, which will help you to get the feel of all the types of telescopes and you will know which one is easier for you to use. A large aperture refractor telescope (大口径折射望远镜) may give you an excellent picture but you may not be able to hold it firmly while using it, which may result in an unclear picture.
There are three types of telescopes that are available on the market. The first type of telescope is the refractor telescope, which provides a good picture but is not as easy to carry as the other two types of telescopes and so you will have to buy one with a small aperture. The second type of telescope is the reflecting telescope, invented by Isaac Newton.There is no added color in the picture caused by refraction of light. This type of telescope is easy to carry and the cheapest of all. The third type of telescope is known as the catadioptric telescope (折反射望远镜), which is the smallest type of all the telescopes and is more popular among astronomers.
1. What will be required if one wants to use a telescope effectively?| A．The patience to search for constellations. |
| B．The ability to recognize constellations. |
| C．The desire to learn about the history of telescopes. |
| D．The willingness to listen to others’ comments. |
| A．One must know something about astronomy and telescopes. |
| B．One can’t buy a telescope without buying several astronomy magazines. |
| C．One should check the telescopes on the market and try to find a better one. |
| D．One must be familiar with new information of astronomy and space instruments. |
| A．To seek advice from some experienced telescope users. |
| B．To get used to using at least one type of telescope. |
| C．To know whether he is really interested in astronomy. |
| D．To bargain with the seller over the price of the telescope. |
| A．Binoculars. |
| B．The catadioptric telescope. |
| C．The reflecting telescope. |
| D．The refractor telescope. |
| A．An Introduction to Astronomy |
| B．Buying A Telescope For the First Time |
| C．The Competitive Market of Telescopes |
| D．The Advantages and Disadvantages of Several Telescopes |
【推荐1】What are the limits of the human body? Is there a point at which it is physically impossible to do something?
“One thing we’ve all learned in the last 30 years or so is that just about anything is humanly possible,” says Dr. Jack Wilmore, author of Physiology of Sport and Exercise. “As time goes by, I think you’ll see more records continue to fall in every sport. The talent pool is better than ever. With more and better athletes joining in and competing, records will fall and new ones will be set.”
Many believed it was physically impossible for a human to run a mile in under four minutes, but Roger Bannister proved that was wrong, with a three-minute, 59-second mile in 1954. Today, sub-four-minute miles are considered ordinary even in high school. And Bob Beamon amazed the whole world in the 1968 Olympics with his historic long jump of 8. 90 metres. In an event where a record is usually broken by me re inches, he broke the previous jump record by more than 21 inches, but even his record was broken in 1991.
One factor is now becoming more understood and paid more attention to: sports psychology (心理学). Getting inside the athlete’s head can be as effective as training and long workouts. According to Wilmore, the psychological factor of sports has become more and more valued. He thinks highly of most teams’ hiring (雇佣) professional sports psychologists to work for their players.
What’s more, everything in the sports field — training, nutrition (营养), injury treatment — is far better than it’s ever been. “Besides, children today are more likely to focus on one or two sports instead of competing in several as was common twenty-five years ago,” Wilmore says. “That means they start concentrating on a sport much earlier and put more effort into it, and thus they become much better at it.”
“There’s a lot we don’t know yet about the human body,” he adds. “And one of those things is can do.” the full range of human potential. It would be foolish to try and put limits on what the human body can do.”
1. What can we learn from Dr. Jack Wilmore’s words?| A．Athletes will become the most popular people. |
| B．It will be tougher for athletes to break former records. |
| C．It is necessary for athletes to learn the limits of the body. |
| D．Athletes will continue to surprise us with their achievements. |
| A．To introduce two great athletes. |
| B．To show some of the latest world records. |
| C．To prove the limits of the body can be pushed. |
| D．To explain what athletes can achieve under stress. |
| A．Appreciative. | B．Unconcerned. | C．Doubtful. | D．Objective. |
| A．They take part in far more sports. |
| B．They are less likely to get injured in sports. |
| C．They begin playing sports at a much earlier age. |
| D．They become more skilful at one particular sport. |
【推荐2】Sugar-free cookies, sugar-free candy, and diet soda—are these better for you? After sugar became a no-no in the nutrition and wellness world, sugar-free food and drinks acted as a replacement for once beloved sweet drinks and snacks. Being claimed to be ZERO sugar means the food and drinks are healthier, better for diabetics, and help you slim down ... Right? Wrong. Sugar-free products aren’t better for you. In fact, they are worse. For most sugar-free products, it means that artificial sweeteners (甜味剂) are used instead of real sugar. The problem is that these sweeteners do not come from natural soures and they can do you more harm than good.
Let’s get into what these artificial sweeteners actually are. Sugar-free sugar sounds wrong because there is no such thing as sugar-free sugar. Some of these sugar-free alternatives even contain sugar and the ones that have chemicals your body often does not know how to process. Most artificial sweeteners are a lot sweeter than sugar so only a small quantity of them are needed. That’s why they can market sugar-free alternatives as “low-calorie” or “no-calorie’. It also means that you get no nutritional value from consuming them, which is why so many sugar-free replacements are classified as “non-nutritive”. These artificial sweeteners tend to hide under some names. Actually, they are 200-600 times sweeter than sugar.When you eat sweet stuff, your body continues to desire it and, even though your body cannot metabolize (代谢) these sugar-free alternatives, your brain does not know the difference. In turn sugar-free alternatives relate to weight gain and Type-2 diabetes. Besides, artificial sweeteners also damage your gut’s ability to break down sugar which impacts everything you eat. In other words, your body doesn’t know how to handle artificial sweeteners because they have nothing real to process.
Here is a good rule of thumb: stay away from artificial sweeteners and look for non-sugar, natural sweeteners like stevia (甜叶菊) or date sugar. In the war against artificial sweeteners and real sugar, both lose. Satisfy your sweet tooth with natural sugar that comes from fruits and stay away from products claimed to be sugar-free.
1. What do most sugar-free products have in common?
| A．They don’t taste sweet. | B．They are free of calories. |
| C．They are rich in nutrition. | D．They have artificial sweeteners. |
| A．They are as sweet as sugar. | B．They pose a big risk to health. |
| C．They can be metabolized easily | D．They have long been added to food. |
| A．To keep a balanced diet. | B．To stay away from sugary products. |
| C．To choose fewer artificial ingredients. | D．To take in sugar from natural sources |
| A．Why are sugar-free products bad for your health? |
| B．How will sugar-free products affect your body? |
| C．What can be called sugar-free products? |
| D．Why are sugar-free products popular? |
【推荐3】Wind power is a powerful tool for reducing carbon emissions that cause climate change. The turbines (涡轮机), however, can be a threat to birds, which is why experts are looking for ways to prevent the danger.
A company in Boulder, Colorado has produced a camera-and-AI-based technology that can recognize eagles and other birds as they approach in enough time to shut off turbines in their flight paths. Their tool, called IdentiFlight, can detect 5.62 times more bird flights than human observers alone, with an accuracy rate of 94 percent. Using high-precision (高精确度的) visual sensors, the system calculates a bird’s speed and flight path, and if it is on a crash path with a turbine, a signal is sent to shut that turbine down.
Winning an award for its performance in Australia, the tracking system was set up in 2018 and was found to cut eagle deaths at the Cattle Hill Wind Farm by more than four-fifths. Each day signals have shut down their movements an average of 400 times—across the field of 48 turbines— for 2 to 3 minutes each time.
Across the globe, Duke Energy in Wyoming is employing the same technology with impressive results at its Top of the World Wind power Project, which was the first wind site to use the technology. In 2014, IdentiFlight’s maker, Boulder Imaging, used Top of the World for testing after eagles were killed by the turbines, which left Duke Energy in violation (违反) of the Migratory Bird Treaty Act. 47 units made of eight wide-angle cameras now constantly pass cross the sky to monitor all 110 turbines.
Bird lover Garry George admits, “Our own science shows that climate change is by far the biggest threat to birds and the places wildlife need to survive. IdentiFlight will make it possible to fight the worst effects of climate change and protect the birds we love in the process.”
1. What can IdentiFlight do?| A．Stop the turbines when birds are spotted. |
| B．Prevent birds from choosing a crash path. |
| C．Identify potential threats to wind turbines. |
| D．Let the turbines make full use of wind power. |
| A．It is widely used. | B．It received a warm welcome. |
| C．It is very effective. | D．It has a really long service life. |
| A．It broke the relevant law on bird protection. |
| B．It responded to the call of Boulder Imaging. |
| C．It intended to improve its wide-angle cameras. |
| D．It followed in the Cattle Hill Wind Farm’s footsteps. |
| A．Reserved. | B．Approving. |
| C．Uncertain. | D．Unconcerned. |
