As global temperatures continue to rise, more “extreme rain” events—intense, cats-and-dogs down pours—can be expected, said the study, published Monday in the journal Nature Climate Change. And that, scientists said, means an increased flood risk, particularly for the world's driest areas. The study challenges the idea that global warming is causing dry areas to become drier and wet areas wetter.

    “In both wet and dry regions, we see these great increases in heavy precipitation（冰雹）,” lead author Markus Donat, a climate scientist at the University of New South Wales, told Nature.

    Donat and his team collected data from 1951 to 2010 on extreme precipitation events from 11, 000 weather stations around the world, Nature reported.

     In that time, the number of days with“extreme precipitation” increased 1 percent to 2 percent per decade.

  “We found a strong relationship between global warming and an increase in rainfall, particularly in areas outside of the tropics,” Donat said in a statement.

  “Importantly, this research suggests we will see these extreme rainfall events increases at regional levels in dry areas, not just as an average across the globe,” Donat added.

    Peter Stott, a senior climate scientistat Met Office, told Climate Central that the study's findings are important, because more violent rainfall and flooding will “challenge our capability toadapt to a rapidly changing climate.”

    As Nature reported, the researchaligns（结盟）with a 2015 study that found global warming has led to a sharp increase in record-breaking precipitation events. Donat told Nature that his study should come as a warning to world governments.

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。

    Christmastime in the city brings forests of trees already cut and waiting to be sold. But some people like to drive to tree farms. Others wait for their trees to come to them. They order one from the pages of a catalog or on the Internet. Some say the easiest thing of all is to buy a man­made tree with Christmas lights already on it. No falling needles to have to clean up.

    The National Christmas Tree Association says 33,000,000 real trees were sold last year, compared to 9,000,000 man­made ones. Man­made trees generally cost more, but they can be reused. Most natural trees are cut up and recycled, but some people buy trees that can be planted.

    Most Christmas trees are now grown on farms instead of in forests. Twenty-one thousand tree farmers in the United States grow Christmas trees on more than 180,000 hectares. Oregon was the leading producer last year.

    Twenty-two percent of people who bought real trees last year chose them at a farm. Two percent of those people cut the trees themselves. The next most popular places were big stores like Walmart and Home Depot. Groups like the Boy Scouts also sell Christmas trees. But some people pay nothing for theirs. They steal it.

    Cornell University in Ithaca, New York, has many pretty evergreens. Some years ago, a university worker found a way to keep them there. A month before Christmas, workers treated them with “pink ugly mix”. It contains water and red food colour. The bright colour starts to disappear after about a month. It can take longer, however. Cornell decided not to use the mix this year, but the idea has spread.

    Kids are natural scientists. That may be why they ask so many questions.

    Younger kids take up science and math with amazing enthusiasm, yet as they get older they often lose their excitement. Children look on scientific exploration as play, but as they get older they start to connect it with big heavy books, long worksheets and a lot of really confusing words.

    What a tragedy! We had their attention, they were listening, they were participating, they were learning and then we lost it to boredom.

    We need our kids to play more. More play brings up basic scientific concepts(概念). Being familiar with basic scientific concepts brings about exploration which leads to research. Once they are researching, they are completely into the learning.

    My boys built a small 9­hole golf course next to our driveway one day. It was a great product of science. They dug out the holes and channels to guide the golf ball. They played with architecture(建筑学)with a series of pipes they had found in the garage. They tested speed and momentum(动量)by creating one of the holes across the driveway. They experienced biology when deciding which front yard plants could be used as a part of the course and which needed to be pulled up.

    If I had sent them out to the yard to build a 9­hole golf course, it would have never happened. It was because it was their idea that it worked. I try to tell them some of the concepts after the fact. When they ask about something, I try to relate it back to something they have built, experienced, or felt. I try to give them a vocabulary around what they already know.

    An afternoon can change the way kids look at the world. Not bad for a day of play.

The thing that sets children apart from adults is not their ignorance, nor their lack of skills. Rather, it's their enormous capability for joy. A friend told me a story. One day, when she went to get his 6-year-old son from soccer practice, her kid greeted her with a sad face. The teacher had criticized him for not focusing on his soccer drills. The little boy walked out of the school with his head and shoulders hanging down. He seemed wrapped in sadness. But before reaching the car door, he suddenly stopped, crouching(蹲伏) down to look at something on the sidewalk. “Mom, come here! This is the strangest bug I've ever seen. It has, like, a million legs. It's amazing!” The little face was overflowing with indescribable excitement.

Nowadays, however, when we walk into a classroom, especially in a high school, we'll be choked by towering books and papers, and hiding behind them are a group of motionless creatures, pens in hand, minds dry, just as the hollow men portrayed by T. S. Eliot. Their pursuit of joy has given way to their hunger for grades. Laughter and happiness are a distant memory for them.

    Although joy is an unaffordable luxury in today's increasingly fierce competition, administrators and teachers need a mindset shift from crushing students with assignments to getting them to take pleasure in productive activities which develop their important qualities, like perseverance and obligation. The assumption that pleasure is the enemy of competence and responsibility makes no sense educationally.

Adults tend to talk about learning as if it were medicine: unpleasant, but necessary and good for you. Why not think of learning as if it were food—something so valuable to humans that they want to experience it as a pleasure?

    Military training has long been considered a ritual (仪式) that freshmen must go through in order to officially start their college lives. While some question the necessity of such training. Many students see military training as a campus tradition that should be maintained.

    Early in February, the Ministry of Education issued a new regulation that colleges and universities should carry out a minimum of 14 days compulsory military training for freshmen.

    In a report by Beijing Evening News, Hou Zhengfang, a Beijing-based education PhD, questioned the benefits of military training. "The training routine does little to improve students' physical fitness over only two weeks' time. Maybe some disaster prevention training, such as earthquake survival or escaping from fires would be of greater benefit."

    Meng Yang, a 19-year-old freshman at Guangxi University, fainted during training. She said that many students, especially girls, are willing to train under direct sunshine. "For me, military training is physically challenging and even damages my health."

    According to Li Jian from the student affairs office of Guangzhou University, feeling dizzy happens frequently during military training and the school has received a lot of complaints from both students and parents: "But I still think military training is a good thing. Students are easier to manage after the military training. They became more positive about their new environment after the training."

    Although autumn is fast approaching Beijing, the noon heat burns 3300 freshmen on Tsinghua University's campus. Chu Jinjing, a freshman majoring in medicine, did feel some discomfort while training in sweaty clothes in the glaring heat, the 18-year-old still enjoyed being part of group going through strict exercises. "By going through this tough training, students bond faster and a sense of belonging to the school can be formed. I've made a lot of friends already."

    According to the Ministry of Education, the purpose of military training is to teach students discipline, the spirit of teamwork and endurance. But in reality, according to Xiong Bingqi, deputy director of the 21^stCentury Education Research Institute, the effect is not satisfying. "Such goals require long-term development. It is unrealistic to expect military training to make a difference in only 14 days." He thus suggests that it should be up to schools to conduct military training in a way that best suits their students.

    However, Wang Wenhui, an 18-year-old freshman from Xi'an Jiaotong University, sees military training as a tradition that reaches beyond character building. "From junior and senior high school to college, we join military training to start a new journey. I would feel a bit incomplete without it."

D

With the completion of the Human Genome（基因组）Project more than 20 years ago, and the discovery of the double helix structure of DNA enjoying its 70th birthday last year, you might assume that we know how life works. Think again!

Evolution has a 4bn-year head start on us. However, several aspects of the standard picture of how life works-the idea of the genome as a blueprint, of genes as instructions for building an organism, of proteins as precisely tailored molecular（分子）machines and more-have wildly reduced the complexity of life. 

In the excellent book How Life Works, Philip Ball explorers the new biology, revealing life to be a far richer, more delicate affair than we have understood. Ball explains that life is a system of many levels-genes, proteins, cells, tissues, and body modules-each with its own rules and principles, so there is no unique place to look for an answer to it. 

Also, How Life Works is a much more appealing title than the overused question of "What is life?". We should be less concerned with what a thing is, and rather more focused on what a thing does. Defining a living thing implies an unchangeable ideal type, but this will run counter to the Darwinian principle that living things are four-dimensional, ever changing in time as well as space.

But it's an idea that is deeply rooted within our culture. Ball points out that we rely on metaphors（比喻）to explain and explore the complexities of life, but none suffice. We are taught that cells are machines, though no machine we have invented behaves like the simplest cell; that DNA is a code or a blueprint, though it is neither; that the brain is a computer, though no computer behaves like a brain at all.

Ball is a terrific writer, pumping out books on incredibly diverse subjects. There's a wealth of well-researched information in here, and some details that are a bit chewy for the lay reader. But the book serves as an essential introduction on our never-ending quest to understand life.