Yesterday and Today

    Life in the twenty-first century will be different from life today. Between then and now many changes will take place, but what will the changesbe?

    The population is growing fast. There will be many people in world and most of them will live longer than people live now.

    Computers will be much smaller and more useful, and there will be at least one in every home. And computer studies will be one of the important subjects in schools then.

    People will work fewer hours than they do now and they will have more free time for sports, watching TV and travel. Traveling will be much cheaper and easier. And many more people will go to other countries for holidays.

    There will be changes in our food, too. More land will be used for building new towns and houses for all the people. Then there will be less room for cows and sheep, so meat will be more expensive. Maybe no one will eat it every day. Instead they will eat more fruit and vegetable. Maybe people will be healthier.

    Work in the future will be different, too. Dangerous and hard work will be done by robots. Because of this, many people will not have enough work to do. This will be a problem.

    Imagine that you're the creator and show runner of the newest comedy show on television. Only it isn't so popular yet, and your live Studio audience isn't giving you the big laughs the show deserves. Do you film the show all over again, hoping that this time the audience will laugh? Or is there another option for making a joke sound funnier than it was received?

    Sweeten(改善) the sound by adding a laugh track! “Sweetening,” or the addition of sound effects such as laughs, screams, and other audience-produced noises to the audio track of a TV show, has been used since the 1940s to produce the appearance, or rather the sound, of an engaged and entertained response to a show's comedy. Laugh tracks came into existence as not only a solution, and sometimes replacement, for an unengaged live audience but also as a way to engage an at-home audience into a more-traditional, public, and theaterlike experience. Adding a laugh track to a television show makes the viewers at home feel much less like they're sitting on a couch staring at the television screen and much more like they're in a room full of laughing happy people to varying degrees of success.

    Though the art of sweetening has risen and fallen in popularity over the past 60 years, credit for its creation and continued use is owed to laugh-track pioneer and sound engineer Charles Douglass. Douglass was the first to develop, in 1953, a machine for producing “canned laughter”, accessible at the push of a button or pull of a lever (操纵杆). Despite being artificial, sensibly edited laugh tracks are found by television studios to bring about a positive audience response, as their use is usually accompanied by higher ratings and increased audience memory. Though some television audiences may disagree with the value of the laugh track, the cheerful and repetitive sound holds a permanent place in the history and future of television comedy.

The Domestication （驯化）of Cats

    For centuries, the common view of how domestication had occurred was that prehistoric people, realizing how useful it would be to have animals kept for food, began catching wild animals and breeding （繁殖）them. Over time, by allowing only animals with "tame"（驯养）characteristics to produce their babies, human beings created animals that were less wild and more dependent upon people. Eventually this process led to the domestic farm animals and pets that we know today, having lost their ancient survival skills and natural abilities.

    Recent research suggests that this view of domestication is incomplete. Prehistoric human beings did catch and breed useful wild animals, but specialists in animal behavior now think that domestication was not simply something people did to animals—the animals played an active part in the process. Wolves and wild horses, for example, may have taken the first steps in their own domestication by hanging around human settlements, feeding on people's crops and getting used to human activity. The animals which were not too nervous or fearful to live near people produced their babies that also tolerated humans, making it easier for people to catch and breed them.

    In this version, people succeededin domesticating only animals that had already adapted easily to life around humans. Domestication required an animal that was willing to become domestic. The process was more like a dance with partners than a victory of humans over animals.

    At first glance, the laming of cats seems to fit nicely into this new story of domestication. A traditional theory says that after prehistoric people in Egypt invented agriculture and started farming, rats and mice gathered to feast on their stored grain. Wildcats, in tum, gathered at the same places to hunt and eat the rats and mice. Over time, cats got used to people and people got used to cats. Some studies of wildcats, however, seem to call this theory into question. Wildcats don't share hunting and feeding areas, and they don't live close to people. Experts do not know whether wildcats were partners in their own domestication. They do know that long after people had acquired domestic dogs, sheep and horses, they somehow acquired domestic cats. Gradually they produced animals with increasingly tame qualities.

    In recent years more and more Chinese schoolchildren are required to wear uniforms at school. Do American children wear school uniforms? In fact, American schoolchildren often wear uniforms if they attend religious or other private schools. Most public schools do not require uniforms. But over the last ten years or so, more of them have moved in that direction, including high schools. Another option is that students may just have to dress alike—for example, white shirts and dark colored pants or skirts. Even schools that do not require uniforms generally have a dress rule about what they consider acceptable. Schools commonly forbid clothing that shows images or words causing displeasure, or simply too much skin. Hats may be forbidden because, for example, different colors may be connected with bad guys.

    Some parents like the idea of uniforms. Some say it means they do not have to spend much on clothing for their kids. Others, though, argue that uniforms represent an unnecessary cost.

    There are also debates about whether uniforms or other dress rules go against civil rights. Students and parents have taken legal action against school dress requirements. Several years ago, a middle school was asked to stop its dress rule unless families had a way out of it. The American Civil Liberties Union of Northern California brought the case for the families of several students who had been punished by the school. Most attention centered on a girl who wore socks with the Tigger character from Winnie the Pooh. The school said its clothing policy, including no pictures of any kind, was needed to control a growing problem with gangs. The families argued that the policy went against free speech rights as protected by the United States and California constitutions.

    The United States Supreme Court says student expression is protected as long as it does not harm the work and the rule of a school. But some educators believe dressing alike helps improve student learning. They believe that uniforms help create a sense of unity and reduce the risk of fights. They also say uniforms make it easier for security reasons to tell if someone belongs to the school or not.

    Ride-hailing apps and robot cars promise to change how we get around and the effects are already being felt. Traffic in New York is slowing down. Jams are common in Manhattan, especially in its business districts. Daytime traffic in the busiest areas now moves almost 20% more slowly than it did five years ago.

    It seems a place ripe for wide use of ride-hailing apps that, you might think, would reduce some of the jams. However, those apps appear to be making things worse as traffic has slowed in line with the growing popularity of apps such as Uber and Lyft, a study by transport expert Bruce Schaller suggests.

    Over the four years of the study, the number of cars in Manhattan seeking ride-hailing fares increased by 81%. There are now about 68, 000 ride-sharing drivers across New York. That's about five times the number of the yellow cabs licensed to operate there, he found. There are so many drivers, his work suggests, who spend about 45% of their spare time just touring for fares. That is a lot of unused cars blocking a lot of busy streets.

    Simple physics explains why ride-sharing vehicles are causing, not curing jams, said Jarrett Walker, a public transport policy expert who has advised hundreds of cities about moving people.

    "Lots of people are deciding that, 'Oh, public transport is just too much trouble this morning,' or whenever, which causes a shift from it," he told the BBC. "That means moving people from larger vehicles into smaller ones, which means more vehicles to move the same people. Therefore, more traffic."

    Data gathered about ride-sharing drivers illustrates how they contribute to congestion (塞车), said Prof. Christo Wilson, a computer scientist at Northeastern University who has studied the services. "You can look at the traffic pattern for the Uber vehicles and it perfectly matches the peaks for the rush hour and the peak time of a day," he said. They are out there in force at the worst possible times.

According to a new Agriculture Department report, U. S. forests could exacerbate global warming because they are being destroyed by natural disasters and are losing their ability to absorb planet-warming gases as they get older. The report predicts that the ability of forests to absorb carbon will start declining after 2025 and that forests could release up to 100 million metric tons of carbon a year as their emissions (排放) from decaying (腐烂的) trees go beyond their carbon absorption. Forests could become a "substantial carbon source" by 2070, the USDA report says.

The loss of carbon absorption is driven in part by natural disasters such as wildfires, tornadoes and hurricanes, which are increasing in frequency and strength as global temperatures rise. The disasters destroy forestland, destroying their ecosystem and decreasing their ability to absorb carbon, according to Lynn Riley, a senior manager of climate science at the American Forest Foundation. Aging forests also contribute. The report found that older, mature trees absorb less carbon than younger trees of the same species, and U. S. forests are rapidly aging.

This trend is likely to continue, as forests come under increasing threat from climate change and exploitation (开采). The typical tropical (热带的) forest may become a carbon source by the 2060s, according to Simon Lewis, professor in the school of geography at Leeds University. "Humans have been lucky so far, as tropical forests are cleaning up lots of our pollution, but they can't keep doing that indefinitely," he said. "We need to cut down fossil fuel emissions before the global carbon cycle starts working against us."

U. S. forests currently absorb 11 percent of U. S. carbon emissions, or 150 million metric tons of carbon a year, equal to the combined emissions from 40 coal power plants, according to the report. The loss of forests as natural carbon absorbers will require the U. S. to cut emissions more rapidly to reach net zero. "As we work to decarbonize (碳减排), forests are one of the greatest tools at our handling. If we were to lose that, it means we will contribute that much more in emissions." Riley said.