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.

    Most people say that most people have not more than 30 friends at any given time, and 400 over the whole of their lives. However, on social networking sites, most users have about 150 friends. If these numbers are correct, then friendship means different things in different situations.

    Also, there are no rules about friendship. There are no instructions about how to make friends, how to keep friendships going, and how to finish friendships if we want to move on. People have very different opinions about this: some people would die for their friends and they value them more than family. Others say that friends are temporary, only there to help each other until they are no longer needed. If people with such different views become friends, this can lead to problems.

    Because of these different definitions of friendship, it is easy to be unhappy about our friendships. We may want them to be deeper or closer, or we may want to have more friends in our lives. Sometimes we simply do not have the time to develop our friendships, or we fear we have left it too late in life to start. If we move to another country or city, we have to find ways, to make new friends again.

    This dissatisfaction shows us how important friendships are for most of us. We should not think that it could be too late to build friendships. We also need to understand that the need to be around other people is one that is shared by many. Therefore, we should not be too frightened about starting to talk to people who in the future may become our friends: it is likely that they too would like to get closer to us. Remember what people say: strangers are friends we have not met yet.

    A new study suggests that people who drank a certain amount of alcohol（酒）had a lower risk of cancer and death than those who drank more or none during a nine-year period. And with each additional drink a week, the risk of cancer and death from any cause increased, the scientists reported.

    However, the study found only an association between alcohol and cancer and death, and did not prove cause and effect, the researches said. What sets the new study apart, said lead study author Andrew Kunzmann, is that previous studies looked at cancer and death separately. “What our study does is combine the two outcomes together and we find that lighter drinking is associated with the lowest risk of cancer or death,” Kunzmann said.

    But Kunzmann noted that the participants（参与者）were all older adults. That means that “we're not really showing what happens in younger people if they drink,” he said. Also, it's difficult to account for other lifestyles that could have affected the results. “These could also influence health. But the results did take into consideration differences in diet, smoking and education among participants,” Kunzmann noted.

    The researchers said that they hope their study sparks conversation about reducing the suggested alcohol intake in countries' guidelines. “We're not telling people what they can or can't do or what they can or can't drink,” Kunzmann said. “We're just trying to give them reliable evidence so that they can make their own informed, healthy decisions.”

    Sue Hendrickson is a self-taught fossil（化石）hunter. As a kid, Sue Hendrickson often walked with her head down. “People said, 'Look up. Smile!” she says. “Now, I realize I was born to look for things and just didn't know it.”

    Sue Hendrickson does more than look—she finds valuable things: Shipwrecks（沉船）with treasure, ancient sunken cities, and in 1990, she found Sue, the world's largest, most complete Tyrannosaurus rex（霸王龙）. Is Hendrickson lucky? Well, maybe. But she also knows how to look.

    “I limit the area where I'm going to look,” she says. No one knew the location of the sunken ship San Diego in the Philippines. For a year, Hendrickson and other researchers searched papers and sailors' diaries. “The descriptions of the ship's sailors led us to the wreck,” she says. The team also used a tool that can respond to metal. This tool found the San Diego. All the work paid off. The 400-year-old ship was complete, with valuable gold and silver coins.

    To find the dinosaur she calls “the biggest animal that ever walked on earth,” Hendrickson started with maps made to search for oil. What Hendrickson found was the largest and most complete T-rex found to date. The T-rex is 42 feet long with 200 bones! Because it is so complete, scientists were able to infer that Sue walked at about 6 miles per hour and did not run faster than 15 miles an hour. Before Sue was discovered, they thought T-rex was much faster. To learn more about T-rex Sue, go to the Field Museum in Chicago.

    There's plenty left to be found, Hendrickson says, including answers to mysterious such as how T-rex lived. “I tell kids that they need to grow up and work them out because all of us old persons haven't yet!”

    You can't always predict a heavy rain or remember your umbrella. But designer Mikhail Belvacv doesn't think that forgetting to check the weather forecast before heading out should result in you getting wet. That's why he created lampbrella, a lamp post with its own rain sensing umbrella.

    The designer says he come up with the idea after watching people get wet on streets in Russia. “Once, I was driving on a central Saint Petersburg street ad saw the street lamps lighting up people trying to hide from the rain. I thought it would be appropriate to have a canopy(伞蓬)built into a street lamp.” he said.

    In addition to the rain sensor, there's also a 360°motion sensor on the biberglass street lamp which detects whether anyone's using the lampbrella. After three minutes of not being used the canopy is closed.

    According to the designer, the lampbrella would move at a relatively low speed, so as not to cause harm to the pedestrians. Besides, it would be grounded to protect from possible lighting strike. Each lampbrella would offer enough shelter for several people. Being installed at 2 meters off the ground, it would only be a danger for the tallest of pedestrians.

    While there are no plans to take lampbrella into production, Belyacv says he recently introduced his creation one Moscow Department, and insists this creation could be installed on my street where a lot of people walk but there are no canopies to provide shelter.

    When the company was small, Google cared a lot about getting kids from Harvard, Stanford, and MIT. But Laszlo Bock, Google's former Senior Vice President of People Operations, said it was the "wrong" hiring strategy. Experience has taught him that there are exceptional kids at many other places, from state schools in California to those in New York. "What we find is that the best people from places like these are just as good if not better as anybody you can get from any Ivy League school," said Bock, who authored a book titled "Work Rules!"

    So what else does Google not care about:

    Grades: Google's data shows that grades predict performance for the first two years of a career, but do not matter after that.

    Brain-teasers: Gone are interview questions such as: Why are manhole covers (井盖) round? How many golf balls can fit in a school bus? "Our research tells us those questions are a waste of time," Bock said. "They're a really coachable skill. The more you practice, the better you get at it."

    Here's what Google does care about:

    Problem solvers: Your cognitive (认知的) ability, or how well you solve problems.

    Leaders: The idea is not whether you were president of the student body or vice president of a bank, but rather "When you see a problem, do you step in and help solve it?" and then critically, "Are you willing to let somebody else take over, and make room for somebody else? Are you willing to give up power?"

    Googleyness: That's what Google calls its cultural fit. It's not "Are you like us?" Bock said. "We actually look for people who are different, because diversity gives us great ideas."

    "What's most important is that people are intellectually humble, willing to admit when they're wrong, and care about the environment around them ...because we want people who think like owners not employees," Bock said.