阅读下列短文：从每题所给的 A、B、C、D 四个选项中，选出最佳选项，将正确的选项涂在答题卡上。

Is there link between humans and climate change or not? This question was first studied in the early 1900s. Since then,many scientists have thought that our actions do make a difference. In 1997,the Kyoto Protocol explained our role in the Earth's changing atmosphere and set international limits for gas emissions(排放) from 2008to 2012. Some countries have decided to continue these reductions until 2020. More recently, the Paris Agreement, stuck by nearly 200 countries, also aims tolimit global warming. But just now how much warmer it will get depends on how deeply countries cut carbon emissions.

    The St. Louis Post-Dispatch reported that the St. Louis Outlet Mall is expanding its restrictions on unaccompanied teenagers. In 2006, a parental-escort (陪同)policy was established: on Fridays and Saturdays starting at 6 p.m., anyone under 17 that isn't accompanied by a guardian who is at least 21 years old will be kicked out of the mall. It was around this time that other malls around the U.S. likewise banned unaccompanied teens during certain evening hours.

Starting from this Friday, the St. Louis Outlet Mall is pushing its parental-escort rule back to 3 p.m. on Fridays and Saturdays. Similarly, the Mall of America expanded its parental-escort policy during the recent holiday shopping season. Normally, the policy bans kids under 16 without guardians(监护人) from 4 p.m. until closing time just on Fridays and Saturdays. But because of a fight in the mall involving dozens of young people that took place on Dec. 18, 2012—- a weekday, the policy was broadened to include peak 2013 holiday shopping hours, including Thanksgiving Day and all of the Christmas week.

    Teen disturbances in other malls may cause more shopping centers to introduce or expand parental-escort policies. The Indianapolis Star noted that two incidents in 2013 in area shopping centers raised the possibility that Indianapolis malls might need to consider banning unaccompanied teenagers.

   Obviously, such bans are aimed at stopping violence and other outbursts involving teenagers. More importantly, from a purely business perspective, these bans aim to attract shoppers who might otherwise be hesitant to go to the mall because of concerns about violence and outbursts involving teenagers. The restrictions allow mall security officers to systematically kick out a group of people that are considered to be loud, thuggish and bad for business overall. But they attract much criticism from online communities. Some argue that teens have the right to shop without a guardian. “Not all teens are disrespectful and troublemakers,” Pamela Chapman wrote. “In fact, it's been my experience that most are good kids.”

Again, the biggest influence on stricter mall policies for teens seems to be that they're just plain good for business. Malls reported strong sales growth after they first carried out the policies six years ago. “We've had some success with the parental-escort policy, and families like shopping out here together,” the manager of the St. Louis Outlet Mall told the St. Louis Post-Dispatch . If there's one rule in retail, it's this—- if a small initiative proves successful in boosting sales, then it's all but guaranteed that a larger initiative will follow.

    What can technology do to make your world better?Three young people are starting new businesses to answer that question.

Mateusz Mach

    Eighteen-year-old Mateusz Mach was the youngest person in Poland to receive money from investors to expand his company.He started Five,a mobile messaging application,or app,for deaf people.The app lets deaf people create their own hand signs to communicate with friends.The app now has more than 10,000 deaf users.And Mach thinks there will be about 150,000 more deaf users in the U.S. next year.There are many different sign languages in various parts of the world.Mach will be working with the United Nations in New York.He says,"I love to create.And I think that the creation of things will be my passion to the end of my life."

    William Zhou

    William Zhou is the co-founder and leader of Chalk.com.The education software company helps teachers from the kindergarten level t0 12th grade,or the end of secondary school.Zhou was born in Beijing,China,grew up in the Canadian city of Vancouver and founded his first company when he was still in high school.Zhou sold the company when he was studying computer science at Canada's University of Waterloo.But he strongly wanted to make a change in education,From his dorm room,Zhou created Chalk.It is a group of programs that supports individual teaching and learning.Based in Canada,Chalk is now used in 20,000 schools by more than 100,000 users worldwide. Zhou says building startups is a difficult process because it could last years."It's only worth it if you find something you truly care about—something you're passionate about.Otherwise,you may just end up crashing."

    George Mtemaharji

    George Mtemahanji was born in the African country of Tanzania and moved with his family to Italy in 2002, where he attended the Technical Institute of Alfredo Ferrari in Maranello.There he learned about renewable energy and began thinking that solar energy would be easier to use in Africa than in Europe.After graduation,he returned to Tanzania in 2014 to start his own solar energy company—Sun Sweet Solar—in partnership with his friend Manuel Rolando.He explains that he could not understand why,in a place with bright sunshine,"more than 90 percent of people had no access to electricity.So when I returned to Italy I spoke with Manuel on the huge electricity demand in Tanzania and to the possibility to open a business there."Sun Sweet Solar found early success in rural areas of Tanzania.Since then,the company has been expanding.He hopes to create jobs and help build his country in the process.He understands the process will take time."But I think we are on the right path."

    Dr. Sasaki knew the first-night effect probably has something to do with how humans evolved.

    The puzzle was what benefit would be gained from it when performance might be affected the following day. She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators (捕食者). This led her to wonder if people might be doing the same thing. To take a closer look, her team studied 35 healthy people as they slept in the unfamiliar environment of the university's Department of Psychological Sciences. The participants each slept in the department for two nights and were carefully monitored with techniques that looked at the activity of their brains. Dr. Sasaki found, as expected, the participants slept less well on their first night than they did on their second, taking more than twice as long to fall asleep and sleeping less overall. During deep sleep, the participants' brains behaved in a similar manner seen in birds and dolphins. On the first night only, the left hemispheres (半球) of their brains did not sleep nearly as deeply as their right hemispheres did.

    Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps (蜂鸣声) of the same tone and irregular beeps of a different tone during the night. She worked out that, if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones. This is precisely what she found.

    Foxes and farmers have never got on well. These small dog-like animals have long been accused (控告)of killing farm animals. They are officially considered as harmful and farmers try to keep their numbers down by shooting or poisoning them.

    Farmers can do call on the services of their local hunt to control the fox population. Hunting consists of hunting a fox across the countryside, with a group of specially trained dogs, followed by men and women riding horses. When the dogs eventually catch the fox, they kill it or a hunter shoots it.

    People who take part in hunting think of it as a sport; they wear a special uniform of red coats and white trousers, and follow strict codes of behavior. But owning a horse and hunting regularly is expensive, so most hunters are wealthy.

    It is estimated (估计) that up to 100,000 people watch or take part in fox hunting . But over the last couple of decades the number of people opposed to fox hunting, because they think it is cruel, has risen sharply. Noisy confrontations between hunters and saboteurs have become so common that they are almost as much a part of hunting as the hunting of foxes itself. But this year supporters of fox hunting face a much bigger threat to their sport. A Labour Party Member of the Parliament, Mike Foster, is trying to get Parliament to approve a new law which will make the hunting of wild animals with dogs illegal. If the law is passed, wild animals like foxes will be protected under the ban in Britain.

Parties and social gatherings no longer excite us the same way they once did. This is not due to a lack of desire to socialize, but the smartphone.

At parties, people focus more on their smartphones than on their drinks. According to a recent study from International Data Corporation，over half of all Americans have a smartphone and reach it the moment they wake up, keeping it in hand all day. In addition, too many people are using smartphones while driving and as a result, they get into car crashes. 34 percent of teens admit to text while driving, and they confirm that texting messages are the major interruption while driving. People's attachment (依恋) to their smartphones is unbelievably becoming more important than the lives of themselves and others.

Just as drivers dismiss the importance of focusing while on the road, many people also fail to recognize the significance of human interaction. When with their friends, some people pointlessly (无谓地) check or send messages in the presence of their friends., which means that their friends are less important. In addition, relying on our smartphones to make friends does not give us the same advantages as making new friends in the real world. Face-to-face conversations will give us the chance to improve our communication skills in the long run.

As many people risk their lives and the lives of people around them just to send a text or mindlessly check their messages, smartphones are in many ways more dangerous to people. The technology shows the achievement weaken the value of communication. Not only is the smartphone affecting our desire to interact face to face, but it is also lowering people's ability to communicate.