1 . Just as a hungry brain craves (渴望) food, a lonely brain craves people. A new brain study demonstrates this. After being left alone, it shows people's brains would be activated at the sight of other people. The action was in the same brain region that speeds up when a hungry person sees food.
Livia Tomova, a neuroscientist, who studies how the brain produces mental activities, and her colleagues began this study. They recruited (招募) 40 people. On one day, the participants had to fast—not eat anything at all—for 10 hours. On another day, the same people were placed in a room for 10 hours. They couldn't see anyone. No friends, no family and no social media. They weren't even allowed to check their email. After both days, Tomova and her colleagues put the people in a MRI machine. It shows activity in the brain by tracking how much blood is flowing to each region.
At the end of each day, the participants showed high activity in a brain area called the midbrain. The scientists were interested in two, small areas within it. Both areas produce dopamine, a chemical that is important in craving and rewards. The two areas activated when hungry participants saw pictures of tasty pizza or juicy hamburgers. After the volunteers had been isolated, those brain areas became active when they saw social activities they missed. It might be playing sports or chatting with friends.
The midbrain plays an important part in people's motivation to seek food or friends. In fact, it responds to food and social signals even when people aren't hungry or lonely. But hunger and loneliness increased the reactions and made people's responses specific to the thing they were missing. And the more hunger or isolation the volunteers said they were experiencing, the stronger the activity in this part of the brain. Tomova and her colleagues published their results November 23 in Nature Neuroscience.
1. How does Tomova test out the result of the study?| A．By stimulating desire. | B．By controlling blood flow. |
| C．By monitoring brain activity. | D．By examining mental activities. |
| A．It consists of two areas. | B．It helps motivate desire for food. |
| C．It stops working when people are full. | D．It decreases responses to lost friends. |
| A．A midbrain area. | B．A social activity. | C．A volunteer. | D．A hamburger. |
| A．Dopamine—a Sure Sign of Age | B．Midbrain—a Nest for the Thoughts |
| C．Hunger Makes Mental Health Struggle | D．Loneliness Makes Our Brains Need People |
2 . Born on May 27,1907 in Springdale,Pennsylvania, Rachel Carson became an avid explorer as well as reader, and took an interest in writing stories.By age 10, she had published her first story in St. Nicholas. She would often read this magazine, as well as many others that concerned the natural world. In 1925, she finished at the top of her class in high school in a class of 45 students.
Carson would go on to attend the Pennsylvania College for Women,which is known as Chatham University now. This is where she would end up pursuing the sciences,in this case biology. She would eventually attend Johns Hopkins University in 1929, continuing her studies in zoology and genetics.
Carson completed her Master' s in zoology in June of 1932, and went to work at a local radio station. Here she would write educational broadcasts for a weekly radio show called Romance Under the Waters. This led her to her job at the U.S. Bureau of Fisheries, and she became just the second woman to be employed by the bureau.
In 1951, Carson had her book The Sea Around Us published,which explains the complexity of the ocean to non-scientists. Carson wrote the book with poetry and science, and she intended to spark in her readers a sense of the fragility of the world' s ecosystem. The Sea Around Us made Carson the voice of public science in America, an internationally recognized authority on the oceans,and established her reputation as a nature writer of the first rank.
In 1962,Carson became well-known when her most famous book Silent Spring was published. This book described the negative effects of pesticides on the environment. Her concern with pesticides dated back to the 1940s,but no one would take her seriously until this book was finally published. On April 14th,1964,Carson passed away due to a heart attack but her work towards preserving the environment has continued to this day. Silent Spring was even republished in 1994 with an introduction from then vice-president Al Gore.
1. What do we know about Carson's early life?| A．She was a great fan of St. Nicholas. |
| B．She worked part-time at a radio station. |
| C．She pursued the sciences in high school. |
| D．She moved to Springdale at the age of 10. |
| A．is a science book for professionals |
| B．was published after Carson passed away |
| C．aimed to raise public environmental awareness |
| D．has made Carson a fiction writer of international significance |
| A．Critical. |
| B．Ambiguous. |
| C．Skeptical. |
| D．Approving. |
| A．Talented and responsible. |
| B．Independent but serious. |
| C．Reliable and courageous. |
| D．Determined but proud. |
3 . Implanted (植入的) devices, such as heart pacemakers, are a valuable part of modern medicine. Their use, however, is limited by the need to renew their batteries and this is a particular problem for those inside the wearer’s head. Therefore, a way to power such implants without replacing their batteries at all would thus be welcome. And Dr Hyuck Choo and his colleagues think they have one. They plan to collect the necessary energy from the vibrations(震动) that occur when someone is talking.
DrChoo’s power plants are small sheets of lead zirconate titanate, a material that produces electricity when it vibrates. He knew that sheets of the size he chose have a resonance (共振) at around 690Hz. This is well above the normal range of the human voice. Using larger sheets would lower the resonance frequency. So he sought to lower a sheet's resonance frequency without increasing its area by caring a special shape out of it. And it worked!
When Dr Choo and his colleagues tested the carved sheets by exposing them to a range of frequencies and monitoring the amount of electricity generated, they found that the voltage was between 100Hz and 120Hz (approximately the common frequencies of adult male vices), and also between 200Hz and 250Hz (the female voice s common frequencies). And, although the amount of power produced is not huge, it seems adequate for the task.
As Dr Choo reported at a conference on January 26, he and his team were able to harvest a tenth of a mill watt per square centimetre of lead zirconate titanate from the voice of a man talking at 70 decibels (分贝), which is normal speaking volume, and tents from someone shouting at 100 decibels Implants usually require a tenth of a mill watt or less to function so this suggests a practical device might be within reach-especially as the vibrations produced by the voice travel efficiently up through the skull, meaning the generator could be put into an implant.
1. What limits the use of implanted devices?| A．The shape of the devices. | B．The effect of the vibrations. |
| C．The need for continuous power. | D．The difficulty in producing the battery |
| A．To renew the batteries of the implants. |
| B．To make the resonance above the human voice. |
| C．To pick out suitable material for his power plants. |
| D．To ensure the resonance of the sheets fit in with the human voice. |
| A．Exposing the sheet to sounds. | B．Powering the implanted devices. |
| C．Lowering a sheet's resonance frequency. | D．Monitoring the electricity produced. |
| A．The voice powered device is likely to be available. |
| B．A man has to shout loudly when using the device. |
| C．The device will be put into production after the conference. |
| D．The generator should be put into the skull when used. |
4 . A newly discovered lizard (蜥蜴) found in the Philippines has made scientists think there might be other never-before-seen creatures on that country’s islands. But scientists say those creatures might never be found because the islands’ rain forests are in danger.
The latest lizard was first spotted in 2001 when scientists saw local people of the island catch it for food. Scientists took some pictures of the lizard. Finally scientists caught a lizard themselves to study. They named the new lizard the Northern Sierra Madre forest monitor because it was discovered in the islands’ Sierra Madre Mountains. The 6.6-foot-long lizard has bright yellow markings that distinguish (区分) it from more boring-looking monitors. Its legs are mainly yellow, and its tail is black and yellow.
So how could scientists work in the Philippines’ rain forests for years without finding the new lizard? They say the Northern Sierra Madre forest monitor is unlike other lizards and their larger cousin, the Komodo dragon. All of those lizards are meat-eaters. But the new-found lizard eats fruit. That means it never has to come down out of the trees. Its uniquely colored skin, quiet manner, and treetop home helped it remain hidden from scientists’ view for many years.
The discovery of the Northern Sierra Madre forest monitor is making scientists realize that Philippines’ rain forests may hold many undiscovered species. But those species will not be found if the rain forests keep disappearing. Twenty years ago, forests covered about 35 percent of the Philippines’ land. But people have been encroaching on that land and building on it. Today, forests cover less than 25 percent of the country’s land.
The rain forests are a “conservation (保护) hot spot” that need to be protected, scientists say. “I hope we can make the new lizard a ‘poster child’ for conservation of the land,” said one scientist.
1. What is the scientists’ attitude to finding more new creatures in Philippines’ rain forests?| A．Interested. | B．Doubtful. |
| C．Excited. | D．Supportive. |
| A．They caught one with the help of locals. |
| B．The locals gave one to scientists as a gift. |
| C．They found it from pictures taken by locals. |
| D．They noticed it when locals hunted the lizard. |
| A．It is a cruel meat-eater. | B．It is the largest lizard in Asia. |
| C．It spends most time in trees. | D．It looks like Komodo dragon. |
| A．Invading.(侵略) | B．Protecting. |
| C．Maintaining. | D．Deserting. |
5 . Compared with solar and wind energy, which are booming, tidal (潮汐的) power is a loser in the clean-energy competition. But if you did want to build a tidal power station, there are few better sites than the mouth of the River Severn, in Britain. Its tidal range, the difference in depth between high and low tides, of around 15 metres is among the largest in the world.
Engineers and governments have been toying with the idea since at least 1925. But none of the suggested projects has materialised. Price is one objection. A study thought that tidal energy might cost between ￡216 and ￡368 ($306-521) per MWh of electricity by 2025, compared with ￡58-75 for seagoing wind turbines (轮机) and ￡55-76 for solar panels. Environmentalists also worry that any plant would change the tides, making life harder for wildlife.
An engineer called Rod Rainey thinks he has a way around both problems. He plans to replace the conventional turbines of previous plans with a much older technology. Specifically, he plans to span (横跨) the river mouth with a line of water wheels. This is a design that dates back to the early days of the Industrial Revolution. Examples can be found fixed to the sides of old watermills (水磨).
But there would be nothing old-fashioned about Mr Rainey’s wheels. Thirty metres high and sixty wide, they would be made from ordinary steel. Two hundred and fifty of them, along with the supporting structures, would be floated into place and secured to the seabed, creating a line 15km long. Together, they could supply power at an avenge ate of 4GW. That is about as much as two biggish nuclear power stations would manage. Substituting one of the wheels with a set of locks would provide a shipping channel about twice the width of Panama Canal, permitting upstream ports such as Avonmouth and Cardiff to continue operating.
1. What is special about the mouth of the River Seven?| A．The tidal range there is about 15 meters. |
| B．It has the largest tidal range in the world. |
| C．The tidal power station has been built there. |
| D．Its power plant makes life harder for wildlife. |
| A．Opposed. | B．Supportive. |
| C．Controversial. | D．Doubtful. |
| A．Support. | B．Transportation. |
| C．Securing wheels. | D．Producing electricity. |
| A．Rainey invented turbines. |
| B．Rainey’s tidal power station. |
| C．Tidal power in the River Seven. |
| D．An old idea might be made practical. |
