阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    It is one of the most annoying words in the English language and it seems there is no escaping it．The word “huh?” is in worldwide use, a study found.

    Researchers discovered that languages spoken in countries from Ghana and Laos to Iceland and Italy all include “huh?”, or something that sounds very like it. They said that while the study may sound silly，the word is an absolutely necessary part of speech. Without it and similar words, it would be impossible to show that we haven't heard or understood what had been said and this would lead to constant misunderstandings.

    But while other words used in the same context, such as “sorry” or “what”, vary widely across languages, “huh?” remains unchanged.

    The Dutch researchers carefully studied ten languages from around the world, including Siwu, which is spoken in Ghana, and an Australian Aboriginal language, as well as Italian, Spanish, Dutch and Mandarin Chinese.

    They analysed tapes of recorded conversations for words that sounded like‘‘huh?”and were used to request that whatever had Just been said be repeated. All contained a version of “huh?” The word was also found in another 21 languages. While there were subtle differences in each country, all sounded basically the same.

    This is surprising because normally unrelated languages will use very different words to describe the same thing. For instance, the Japanese for “dog” is “inu”, while the French is “chien”. It is thought that languages around the world have developed their own version of “huh?” because the sound is quick and simple to form, as well as being easily understood.

    The researchers，said that it might seem unimportant to carry out scientific research into a word like “huh?” but in fact this little word is an essential tool in human communication．They also have an answer for those who claim that “huh?” isn't a word. They say that it qualifies because of the small differences in its pronunciation in different languages. It also can be considered a word because it's something we learn to say, rather than a grunt or cry that we are born knowing how to make.

    Many people wrongly think that cities don't have farms and fruits and vegetables are only grown in the country. Believe it or not, there are more urban farms popping up in cities all over the world.

    Alexandra Sullivan, a food systems researcher in New York, studies urban agriculture. Urban agriculture is another name for farming and gardening in a city environment. Ms. Sullivan studies everything from tiny gardens in empty lots between buildings to bigger fields that have been planted and grown. According to Ms. Sullivan, “Urban agriculture has existed since cities have, across the world.”

    The number of humans living in urban areas, or cities, is increasing. The amount of people who wanted to garden in urban areas is also rising. Ms. Sullivan says, “In small gardens, on rooftops and indoors, city residents grow fruits, vegetables, grains, and herbs, and raise animals to produce milk, eggs, honey, and meat. City residents use these foods as supplements to food produced by rural agriculture.” Even though some people who live in urban areas grow crops, urban residents still need to rely on food grown in rural areas. This is because a city doesn't have enough space to grow enough food for everyone living in it.

    In New York City, urban farmers have come up with many different ways to grow their own produce, even though there isn't a lot of room. For example, Brooklyn Grange is a farming operation that has two rooftop vegetable farms in New York City. All together, the farms are made up of 2.5 acres of rooftop space. This makes Brooklyn Grange one of the largest rooftop farming operations in the world.

    Brooklyn Grange grows all kinds of things. The farming company sells its vegetables to local residents and restaurants. And because the farms are on rooftops, they are specially adapted to their urban location. They use available space that is not needed for anything else. As more urban farmers find ways to grow food in cities, urban residents will be better able to get fresher materials for their meals.

C

    Teens and younger children are reading a lot less for fun, according to a Common Sense Media report published Monday.

    While the decline over the past decade is steep for teen readers, some data in the report shows that reading remains a big part of many children's lives, and indicates how parents might help encourage more reading.

    According to the report's key findings, "the proportion (比例) who say they 'hardly ever' read for fun has gone from 8 percent of 13-year-olds and 9 percent of 17-year-olds in 1984 to 22 percent and 27 percent respectively today."

    The report data shows that pleasure reading levels for younger children, ages2-8, remain largely the same. But the amount of time spent in reading each session has declined, from closer to an hour or more to closer to a half hour per session.

    When it comes to technology and reading, the report does little to counsel(建议)parenst looking for data about the effect of e-readers and tablets on reading. It does point out that many parents still limit electronic reading, mainly due to concerns about increased screen time.

    The most hopeful data shared in the report shows clear evidence of parents serving as examples and important guides for their kids when it comes to reading. Data shows that kids and teens who do read frequently, compared to infrequent readers, have more books in the home, more books purchased for them, parents who read more often, and parents who set aside time for them to read.

    As the end of school approaches, and school vacation reading lists loom(逼近)ahead, parents might take this chance to step in and make their own summer reading list and plan a family trip to the library or bookstore.

    Modern festival-goers who worry about ending up with a dead mobile phone battery after days stuck in a muddy field with no electric plug power points may now have a solution—power boots.

    Mobile phone company European Telco Orange has introduced a phone charging prototype(原型)— a set of thermoelectric gumboots or Wellington boots with a “power generating sole” that changes heat from the wearer's feet into electrical power to charge battery-powered hand-helds.

    The boot was designed by Dave Pain, managing director at GotWind, a renewable energy company. Pain said the boot uses the Seebeck effect, in which a circuit made of two dissimilar metals conducts electricity if the two places where they connect are held at different temperatures. “In the sole（鞋底）of the Wellington boot there's a thermocouple and if you apply heat to one side of the thermocouple and cold to the other side it produces an electrical charge,” Pain said. “That electrical charge we then pass through to a battery which you'll find in the heel of the boot for storage of the electrical power for later use to charge your mobile phone.” These thermocouples are connected electrically, forming an array of multiple thermocouples (thermopile). They are then sandwiched between two thin ceramic wafers(薄片). When the heat from the foot is applied on the top side of the ceramic wafer and cold is applied on the opposite side, from the cold of the ground, electricity is made.

    But the prototype boot does have one shortcoming. You have to walk for 12 hours in the boots to make one hour's worth of charge.

    In the U.S. state of Washington, a road called ^Interstate 90^ cuts through a wild, mountainous area to reach the city of Seattle. For the area's many kinds of animals, the busy highway greatly limits their movements. Crossing 1-90—as the road is called—is a risky but sometimes necessary act. But soon, animals will have a safer choice for crossing the road. They will be able to go above it.

    To help the animals, the state is finishing work on its largest-ever wildlife bridge. The 11-meter-tall, 20-meter-wide structure begins in the forest. It forms two arches above the highway, one for each direction of traffic. Workers are adding fencing and plants to help guide the animals across the bridge. Two-meter-thick walls will help block noise from vehicles below.

    The 1-90 Bridge is part of a growing number of wildlife crossings across the United States. Some are fences, some are overland bridges, and some are underpasses. They all aim to keep drivers and animals away from each other. Collisions between animals and drivers are rarely deadly to people. But they are often deadly to wildlife. In Canada's Banff National Park, studies have found that wildlife crossings reduce the area's animal-driver collisions by 80 percent.

    Most of the wildlife bridges are in western states. But experts have noted many other areas that have a need for such paths. Jen Watkins, whose organization has helped campaign for animal crossings, says finding for more crossings is "the number-one barrier."

    Patty Garvey-Darda of the U.S. Forest Service has worked on the 1-90 crossing from the start of the project. She says the $6- million bridge will one day pay for itself because the highway will not have to be fully or partly closed each time a large animal is struck. She said, ^"If you shut down Interstate 90, you shut down interstate commerce."

    Hotshot jet pilots are no match for cliff swallows. The birds rocket over bridges and skim over lakes, rushing forward at accelerations that would knock an Air Force. By tracking these contests with high-speed cameras, a new study gives the first, in-depth peek into avian aerodynamics (鸟类空气力学) in the wild. "The findings may even provide insight into how to design better micro air vehicles-tiny drones. This technology will be brilliantly useful," says biomechanics expert Jim Usherwood of the United Kingdom's Royal Veterinary College in Hatfield. "High-resolution field studies like this have never been done before for birds."

    For cliff swallows, the trouble starts when they return from wintering in South America to their summer homes in North America. After arrival, they seek out their old mud nests—usually located under concrete bridges and freeways-and start rebuilding their homes. But rather than hunt down a fresh supply of mud, some swallows prefer stealing supplies from their more hardworking neighbors. Others take things further and will even lay an egg or two in their neighbor's nest before taking off.

    Battles in the air follow if the invaders are caught in the act, and a new study takes advantage of these fights to learn how birds perform high-speed maneuvers (演习). The team placed three cameras along a North Carolina lake crossed by a highway bridge that houses several cliff swallow nests and waited for the battles to commence.

The team was surprised to learn that most of the time, chasers copied the move of fleeing invaders. Swallows also pull very hard turns to escape an enemy, with one extreme case reaching 7.8 gravity. Fighter pilots usually pass out at about 5 or 6 gravity, which is why these experiments have earned interest, and partial funding, from the Office of Naval Research. The Navy may use the findings to build better guidance systems for micro air vehicles. However, the swallows' biomechanics are complex, and now the team is simply trying to collect a few tricks.