Biologists who study evolution (进化) have always been interested in animals that developed on islands. In some situations, animals on islands changed over time and came to look very different from the same species that lived on the mainland.
The experts point to animals such as the dwarf elephant that once lived on the Mediterranean island of Cyprus. The animal is now extinct. When it lived, however, it was only the size of a small horse. Elephants that live today in Africa and Asia are much larger than that. In the West Indies, researchers found a giant rodent (啮齿动物) that looked like a rat. However, it was about the same size as an American black bear. Rats are, of course, many times smaller than bears.
Evolutionary experts came to call this phenomenon “island effect”. They used this term to describe the fact that animals who normally have small bodies “upsize” on an island, while the opposite is true for animals who usually have large bodies.
The “island effect” produces strange-sized animals because large animals require more food than small animals. On an island, there is a limited amount of food. As a result, larger animals become smaller over generations in order to survive with lower food intake. For small animals, there is not as much risk from predators on an island, so they often grow larger.
Recently, researchers released their findings about 1,231 existing animals and 350 extinct ones that represent 23 million years of life. They found that animals on islands were more at risk of extinction compared to their relatives on the mainland. The arrival of human settlers increased the extinction risk for these strange animals.
Roberto Rozzi, a paleoecologist at Martin Luther University Halle-Wittenberg in Germany said that the extinction line has become even sharper in recent decades.
The researchers call the islands “biodiversity hotspots”. Even though they only make up 7 percent of the Earth’s land mass, they account for 20 percent of the land species.
1. Why are the animals introduced in paragraph 2?| A．To compare the two species. | B．To lead in the “island effect”. |
| C．To show two kinds of rare animals. | D．To stress the change of surroundings. |
| A．Animals of normal small bodies “upsize” on an island. |
| B．Animals of normal small bodies “downsize” on an island. |
| C．Animals of normal large size have small bodies on an island. |
| D．Animals of normal large size have larger bodies on an island. |
| A．Some things never change. | B．The gain outweighs the loss. |
| C．Humans live in harmony with nature. | D．The fittest animals survive in natural selection. |
| A．The History of Unique Island Animals | B．The Benefits of Saving Island Animals |
| C．Unique Island Animals at Greater Changes | D．Biological Diversity Threatened by Humans |
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【推荐1】The narwhal is a mysterious resident of the remote Arctic. The species, a relatively small whale is known for growing a spiral tusk （螺旋长牙）that resembles the historical description of a unicorn's horn.
Experts have long speculated why narwhals have this strange long tooth. Some think that the tusk is a tool for survival, as they could possibly use it to break up ice or spear fish for meals. However, the vast majority of female narwhals don't have tusks, and females tend to live longer than males. Most scientists now think the tusk provides no advantage for survival, but rather acts as a sex characteristic and determines the social rank. But the tusk may also have another purpose. A 2014 study found the narwhal's tusk is full of sensitive nerve endings that allow the whale to detect changes in the environment, such as changes in temperature and salinity. The finding suggests that the tusk might also be a sensory organ.
Narwhals are an important subsistence resource （生存资源）for high Arctic communities. They provide the humans with high-calorie fat, protein and nutrients, vital and hard to come by in the harsh northern winters. Narwhal tusks were carved into artworks and sold to support families with few job opportunities.
Narwhal tusk is protected now. But similar to all other Arctic wildlife, narwhals are likely to struggle in the face of climate change. Warm temperatures in the Arctic have caused sea ice to disappear at an alarming rate. New shipping channels have become accessible, threatening narwhals and other marine mammals. Researches suggest that narwhals are the most vulnerable （易受伤害的）marine mammals to human activities in the Arctic because these isolated creatures are highly sensitive to ship activities. Their response to changing conditions near the pole could provide insight into larger changes in Earth's future.
1. What does the underlined word "speculated" in paragraph 2 probably mean?| A．Known. | B．Guessed. |
| C．Overlooked. | D．Concluded. |
| A．It is an indicator of gender. |
| B．It reveals narwhals' social rank. |
| C．It can sense changes in the water. |
| D．It can be used to dig fish for meals. |
| A．The conservation of narwhals is a must. |
| B．The situation of climate change is under control. |
| C．Some human activities affect mammals slightly. |
| D．Narwhals are under the threat of being hunted. |
| A．Research on Narwhals' Tusk |
| B．Insight into Climate Changes |
| C．Narwhals ： Feature and Behavior |
| D．Narwhals ： Mysterious Sea Unicorns |
【推荐2】In San Francisco, a large group of sea lions move themselves out of the bay waters and hang out on PIER 39, which is a popular tourist destination. According to dock (码头) officials, this is the most sea lions seen in the region in 15 years.
“Over 1,000 sea lions have been counted this week,” PIER 39 harbormaster Sheila Chandor told many different media. “The surge in sea lions is usually a good sign of their strong population and healthy living environment,” said Adam Ratner, Director of Conservation Engagement at the Marine Mammal (海洋哺乳动物) Center in Sausalito, California.
“California sea lions are sentinels (哨兵) of the ocean,” Ratner said. Their population to some extent reflects the health of the ocean. Therefore, seeing a large number of California sea lions is clearly a good thing.
For nearly 35 years, the slippery (滑的) residents have been a star attraction for tourists. That autumn in 1989, PIER 39 had just been repaired, but the ships had not yet been moved back. At that moment, the sea lions unexpected arrival not only attracted fans but also created enemies. According to a website, some dock residents and workers were scared away by the strong and very unpleasant smell and noise of their new neighbors, while others saw these animals as a bright spot after the destructive Loma Prieta earthquake.
The officials sought help from the Marine Mammal Center to find a way to deal with sea lions. Ratner said that the final decision is to let the sea lions stay and coexist with humans. “The fact proves that this is really a good thing,” he said. “This is just a proof of how we can truly work together and think about how we can share our coasts with marine mammals and other wildlife in a way that benefits all the parties involved.”
1. How does the author start the text?| A．By describing a situation. |
| B．By answering a question. |
| C．By holding a conversation. |
| D．By comparing different opinions. |
| A．Sharp increase. | B．Tight control. |
| C．Slow development. | D．Sudden movement. |
| A．Doubtful. | B．Uninterested. |
| C．Supportive. | D．Unclear. |
| A．Sea lions are pretty cool animals. |
| B．Animals and humans can live in harmony. |
| C．Watching sea lions might not be a proper action. |
| D．Sea lions should be driven out of PIER 39. |
【推荐3】There are many fascinating aspects of ant life, but none may be a more practical lesson for us than their gift for avoiding traffic jams.
A new research paper published in the journal eLife reveals how ants keep traffic flowing by changing their behavior to meet changing conditions. For their experiments, researchers from the University of Toulouse and the University of Arizona focused on Argentine ants that frequently move from one colony to another depending on the proximity (临近) of food sources.
Exploring the Argentine ants’ gift for fast commutes, the researchers built bridges connecting their colonies. The bridges varied in width from a fifth to three-quarters of an inch. The colonies, too, were of different sizes, ranging from 400 to more than 25,000 ants. Essentially, researchers built a new infrastructure (基础设施) system for the ants, connecting their biggest cities to the smallest villages. Then they sat back and monitored the traffic.
To their surprise, even when those narrower bridges reached near capacity, there were no 20-ant pile-ups. Indeed, there was never a hold-up. Traffic remained steady regardless of how overburdened the infrastructure was because ants were able to adjust to the change of road conditions. At some point, when the bridges got really busy, ants moved not so much as individuals but rather like water flowing in an ever-constant stream.
“When density on the trail increased, ants seemed to be able to assess crowding locally and adjusted their speed accordingly to avoid any interruption of traffic flow,” the authors note in a news release. “Moreover, ants kept themselves from entering a crowded path and ensured that the capacity of the bridge was never exceeded.” Argentine ants are extremely effective in getting to where they need to be in a hurry.
The lesson for humans? The traffic problem may lie in our inability to adjust our driving habits for the good of the whole. “Traffic jams are everywhere in human society where individuals are pursuing their own personal objectives,” the authors write. “In contrast, ants share a common goal: the survival of the colony, and thus they are expected to act cooperatively to optimize (优化) food return.”
1. How do the ants keep traffic flowing?| A．By monitoring the traffic flow. | B．By adjusting to the road conditions. |
| C．By communicating with each other. | D．By building their own paths. |
| A．They scrambled to pass automatically. |
| B．They flowed in the stream constantly. |
| C．They moved on individually in a hurry. |
| D．They changed their speed accordingly. |
| A．To raise traffic safety awareness. | B．To give up individuals’ ambitions. |
| C．To act for the good of the whole society. | D．To find solutions to present problems. |
| A．How Argentine Ants Move on the Roads |
| B．Interesting Exploration of Ants’ Gifts |
| C．A New Research Paper on Ants |
| D．Ants Teach Us How to Avoid Traffic Jams |
【推荐1】Neck pain is a widespread complaint in the information age, with many more of us spending a great deal of time glued to a computer, tablet or phone, or sitting in front of the TV. It’s also a common disease of aging, due to increasing wear and tear on the spine’s (脊椎) joints and tissues. At any given time, an estimated 39 percent of people over 65 have discomfort in their necks. Assuming an injury or potential disease isn’t causing the condition, here are some tips from some experts for managing the discomfort, as well as the best stiff (僵硬) neck remedies.
Sleep off a stiff neck. If you’re looking for stiff neck relief, getting a good night’s sleep — which represents roughly a third of your day — is a good place to start. Choose a relatively firm mattress (床垫) and use only enough pillows to keep your head level with the rest of your body — one is usually sufficient. For sleep that is even more neck-friendly, try lying on your back with pillow support under your knees. This will flatten and relax your spinal muscles.
When it comes to computer use, make sure the monitor is at arm’s length and eye level. Laptops have poor posture built into their designs: if the keyboard is near enough to be comfortable, then the screen is too close, and if the screen is positioned correctly, the keyboard is too far away, forcing you to bend forward. You can solve this problem by placing the device on a bunch of large books or a laptop stand and using a separate keyboard and mouse.
There is evidence to suggest home exercises may be effective against short-term neck discomfort (lasting for 12 weeks or less). “There are many possible reasons for neck pain, including stress, poor posture and organ aging,” explains Dr Michael Westaway, a musculoskeletal clinical specialist. “Treatment is often varied and may include an exercise program. For severe cases, there are painkillers, injections and surgery. However, resist the urge to immediately take aggressive measures, since simpler steps will often ease this everyday pain,” Michael Westaway warned.
1. Why do people suffer more from neck pain in the information age?| A．Various stresses from work. | B．More access to the digital facility |
| C．Poor diets and unhealthy eating habits. | D．Higher cost of going to see the doctor. |
| A．More pillows to support your head. |
| B．Less than 1/3 of your day for sleeping every day. |
| C．Sleeping on your back with pillows under the knees. |
| D．Selecting a relatively soft and comfortable mattress. |
| A．Applications. | B．Technologies. | C．Position of the body. | D．Size of the laptops or computers. |
| A．Physical exercises every day is the only way for the neck suffering. |
| B．Painkiller is the immediate solution to neck pain. |
| C．There’s no cure for severe neck pain sufferers. |
| D．Simple steps of neck exercises really works. |
【推荐2】Astronauts in the space stations for long missions often work very long days.Tasks are scheduled (安排) so tightly that break times are often used to finish the day’s work. It’s especially hard for long missions on the International Space Station (ISS). ISS crew members usually live in space for at least a quarter of a year. They work five days on and two days off to mimic the normal way they do things on Earth as much as possible. Weekends give the crew valuable time to rest and do a few hours of housework. They can communicate with family and friends by email, Internet phone and through private video meetings.
While astronauts cannot go to a baseball game or a movie in space, there are many familiar activities that they can still enjoy. Before a mission, the family and friends of each ISS crew member put together a collection of family photos, messages, videos and reading materials for the astronauts to look at when they will be floating 370 kilometers above the Earth. During their mission, the crew members also receive care packages with CDs, books, magazines，photos and letters. Today, the Internet can be used on the ISS, giving astronauts the chance to do some “web surfing” in their personal time. Besides relaxing with these more common entertainments, astronauts can simply enjoy the experience of living in space.
Many astronauts say that one of the most relaxing things to do in space is to look out of the window and stare at the universe and the Earth’s vast land mass and oceans.
1. What does the word “mimic” in Paragraph 1 probably mean?| A．Find. | B．Copy. | C．Change. | D．Lose. |
| A．get more pleasure in space than on the Earth | B．find living in space a bit boring and tiring |
| C．regard space life as common | D．love to see the Earth from space |
| A．work for longer missions in space | B．connect with people on the Earth |
| C．observe the Earth from space | D．spend their free time in space |
| A．They are caring and thoughtful. | B．They are worried and upset. |
| C．They are impatient and annoyed. | D．They are excited and curious. |
【推荐3】Out in the Atlantic Ocean, roughly 60 miles off the northwest coast of Africa, lie the Canary Islands. In the 1950s, the boom in package tourism showed promise as a new cash crop. But while the Canary Islands had the sunshine, warm climate and ease of access from Europe needed for this new industry, they were missing a vital element—picture-postcard sandy beaches.
So the developers on Tenerife in the Canary Islands constructed a breakwater (防波堤) over half a mile long. And then, from the Western Sahara on Africa’s northwest coast, they shipped in 270, 000 tons of sand. By 1973, the project was complete. As anticipated, tourists arrived. Along the engineered beach, rows and rows of tourists relax on beach chairs under umbrellas or walk across soft sand to cool down in the water.
Unanticipated was what their presence gave to one of the world’s most endangered fish species, angel sharks—visibility. The gentle wind creates tiny waves on the water’s surface, a magical cover for what lies beneath—an angel shark nursery. Female angel shark regularly migrate (迁徙) to these ideally sheltered waters to give birth to pups (幼崽), who remain in the shallows for about a year. Feeding on small fishes, they grow to around the same length as a newborn human baby.
Surveys have shown that other beaches in the Canary Islands are also potential nursery sites. Interestingly, most of them have been remade to make them more attractive to people. Playa Chica has another long sweep of imported sand. It’s an attraction for divers as well as angel sharks, so the number of sightings of mature angel sharks of this shoreline is one of the highest in the islands.
Normally, environmentally disruptive projects are bad for wildlife. But what’s clear is that after the breakwater was built and the sand arrived, people followed, and in the calm, shallow waters they began to see baby angel sharks. And unlike how many an association between humans and wildlife ends－in conflict and dead animals－this time it led to conservation.
1. How did the developers attract tourists to Tenerife?| A．By building a base for shipping. | B．By promoting local culture. |
| C．By importing sand to create beaches. | D．By offering discounts on package tour. |
| A．It gave angel sharks a home. | B．It made a magical tourist attraction. |
| C．It caused the disappearance of some fishes. | D．It created conflicts between sharks and tourists. |
| A．Engineered beaches are good for angel sharks nursery. |
| B．Beaches are remade to attract more foreign tourists. |
| C．Playa Chica is well-known for its beautiful shortline. |
| D．Playa Chica has the highest number of angel sharks. |
| A．The economic benefits of developing the Canary Islands. |
| B．The impact of tourism on the environment of the Canary Islands. |
| C．The unexpected benefits of beach development for angel sharks. |
| D．The challenges faced by the angel sharks in the Canary Islands. |
【推荐1】Pre-school children who spend time together take on one another's personalities, a new research has found. The study shows that environment plays a key role in shaping people's personalities. While genetics still forms the central part of the human psyche (心理), the research finds that personality traits (特征) are "contagious" (传染的) among children. "Our finding flies in the face of common assumptions that personality can't be changed," said Dr. Jennifer Neal, co-author of the study.
The researchers studied the personalities and social networks of two pre-school classes for a full school year. One of the classes was a set of three-year-olds, and the other a set of four-year-olds. Children whose friends were hard-working or outgoing gradually took on these personality traits over time. Psychology expert Dr. Emily Dublin said kids are having a far bigger effect on each other than people may realize.
The new study is not the first to explore the contagious effects of personality traits. A 2015 psychology study found that rudeness at work can be contagious as it travels from person to person "like a disease". The study found that seeing a boss being rude to an employee was enough to cause people to be rude to those around them.
The researchers questioned 6,000 people on the social "climate" in their workplaces, which included offices, hotels and restaurants. They found 75 percent of those who took part said they had been treated rudely at least once in the past year. And the study also suggests that merely seeing other people being subjected to rudeness made it more likely that a person would treat their colleagues in the same way. Rudeness could include leaving someone off an invite to a company event, sending unkind emails, finding fault with others or failing to give praise.
Dr. Torkelson believes companies need to be more aware of the harm that rudeness in the workplace can do as it can damage the working environment. She said better training could help to fight against the problem.
1. What does the underlined part "flies in the face of" in Paragraph1mean?| A．Leads to. | B．Results from. |
| C．Goes against. | D．Agrees with. |
| A．Their parents. | B．Their friends. |
| C．The researchers. | D．The psychologists. |
| A．Ignoring the faults of co-workers. |
| B．Not sending emails to workmates. |
| C．Seeking praise from colleagues and bosses. |
| D．Not inviting a colleague to a company party. |
| A．One's personality is hard to change. |
| B．One's personality is shaped by genes. |
| C．One's personality traits can spread to others. |
| D．One's personality traits can change overnight. |
| A．a science report | B．a study guide |
| C．a school textbook | D．a technical journal |
【推荐2】Biologists from Boise State University have been making noise in the forests of the western American state of Idaho. They are making noise to study the value of quiet in nature. They want to know how people and animals react to noise pollution.
The researchers placed outdoor speakers on the side of a half-kilometer-long part of a road in the Boise National Forest. For two years, they played the sounds of passing cars through the speakers. Professor Jesse says they found the sounds caused migratory （迁徙的）birds to flee. The birds also failed to gain weight.
Recently, researchers played sounds of machines that are used to remove natural gas from the ground. That sound is heard in natural gas fields throughout the American West. Professor Barber says these experiments are designed to help researchers learn the effects of noise pollution on birds, insects, bats, and people.
"We are testing the idea that these things are coupled -- that as the soundscape gets louder, wildlife suffers. But that also feeds back on to how much people get out of that experience, how much they value it, and thus how much they are willing to protect that same place."
The research team also studied a group of volunteers who watch birds for fun. Mitch Levenhagen is a graduate student in the research team. He measured how much the artificial noise lessened the ability of the birdwatchers to recognize recorded bird songs.
The birdwatchers said the artificial noise affected their ability to recognize bird sounds more than they thought it would. Birdwatcher Jim Lyons said the experiment caused him to value quiet more.
"I moved out of the city to a little place in the country where I wanted it to be quiet. I greatly value that. It is hard to find those places more and more. There are lots of ways to mitigate（减轻） sound. But it is trade-off. There is always a cost. And it comes down to people's values. What do we value more." said Volunteer Janice Engle.
1. What is the purpose of carrying out the research?| A．To prevent people making any noise in their daily life. |
| B．To find out the effect noise has on humans and animals. |
| C．To call on many more people to protect the environment. |
| D．To encourage people to keep quiet while they are in nature. |
| A．impressive | B．unique | C．instructive | D．convincing |
| A．The great importance of quiet in nature. |
| B．The big price humans will pay for health. |
| C．The great value of a sharp sense of hearing. |
| D．The necessity of protecting wildlife in nature. |
【推荐3】After a five-year travel to study plants, animals and fossils (化石) in South America and on the islands in the Pacific, British naturalist Charles Darwin brought the idea of natural selection to the attention of the world in his best-selling book, On the Origin of Species.
Natural selection is the process through which populations of living organisms adapt and change naturally. Individuals in a population are naturally variable. In other words, they are all different in some ways. This variation means that some individuals have characteristics better suited to the environment than others. Individuals with adaptive characteristics — characteristics that give them some advantage-are more likely to survive and reproduce. These individuals then pass the adaptive characteristics on to their children. Over time, these characteristics become more common in the population. Through this process of natural selection, adaptive characteristics are passed on to the next generations. Those organisms that cannot adapt fast enough through natural selection will die out.
Natural selection can also lead to new and distinctly different species. It is one of the processes that drive phylogenesis and help to explain the diversity of life on Earth.
Darwin chose the name natural selection to contrast with artificial selection that is controlled by humans. Darwin and other scientists of his day argued that a process much like artificial selection happened in nature, without any human help. He argued that natural selection explained how a wide variety of life forms developed overtime from a single common ancestor.
Through studying the fossil record, we know that some species may not be able to adapt fast enough through natural selection and many of them that once lived on Earth are now extinct. Dinosaurs are one example. However, human actions such as over hunting and the destruction of habitats have become the main cause of extinctions today.
1. Why do some species die out according to the text?| A．They can’t adapt to the changed environments. |
| B．They fail to learn from their common ancestors. |
| C．They have too many variable individuals in the species. |
| D．They cannot find enough food and starve to death slowly. |
| A．Extinction. | B．Exposure. | C．Development. | D．Replacement. |
| A．Paragraph 1. | B．Paragraph 2. | C．Paragraph 3. | D．Paragraph 4. |
| A．Species’ extinction is slowing down recently. |
| B．Human actions can lead to species’ extinctions |
| C．Measures must be taken to stop eating animals. |
| D．Artificial selection is more important than natural selection. |
