Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures（核心体温）in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity（湿度）.

In very cold climates, there is a constant danger of developing hypothermia（低体温）, which is a life threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0℃. However, differences in persons and even the time of day can cause it to be as much as 6℃ higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4℃. Below 29.4℃, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6℃. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7℃.

In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7℃. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.

    Have you grasped the information taught by your teacher in class? Have you understood what you saw on the screen? Maybe everyone has their own learning style.

    Generally speaking, we gather information with our minds and bodies in different ways, such as seeing, hearing and doing. Then our brains deals with that information, organizing it and connecting it to things we are already aware .In other words, our brains will deal with the information in different ways. Sometimes we think in pictures or words. Sometimes we remember details or the big pictures.

    For different people, their learning styles are different too. One person may find it hard to make out the information in written forms but easy to know it immediately in an oral description. However, another person might find difficulties with the picture but the written message.

    Now scientists say there exist seven basic learning styles.

    Linguistic: These people learn through listening, reading, speaking and writing.

    Logical: These people learn with formula (公式) and principles (原理).

    Visual: These people learn by seeing what they are studying.

    Musical: These people learn well when information is presented through music.

    Kinesthetic: These people learn from movement and physical activities.

    Intrapersonal: These people learn best by linking new information directly with their own experiences.

    Interpersonal: These people learn well by working with others.

    Therefore, if you know what learning style is your strength, you can balance your weakness, and get a more successful learning experience.

    Kendrick Lamar hasn't had much luck when it comes to winning a Grammy. But that's OK： The US rapper(说唱歌手) has just won a Pulitzer Prize for his music.

    In 2014, in 2016, and again this year. Lamar was nominated (提名)for an album of the year Grammy. Each time, he was beaten out, first by Taylor Swift, next by Daft Punk, and most recently by Bruno Mars.

    But the Pulitzer Prize committee was inspired enough by Lamar's 2017 album, Damn, to award the 30-year-old its Pulitzer Prize in music on April 16. It's an amazing album that documents the real life of modem African-Americans in South Los Angeles with wildly accomplished beats and rhythms.

    Lamar's win is considered to be historical. 'The Pulitzers have long displayed their preference toward high art rather than the pop culture of the masses. So it's not just that no rapper has ever won a Pulitzer: no pop music maker has ever won one in the award's 75-year history.

    But Lamar is not just a singer—he's clever at using language. Like the best writers, his music describes small moments that illustrate (阐明) larger points. His songs are about his experience as a black man who grew up in California, struggled, got into trouble, and found his way out by working hard and making sense of the history and reality of racial problems in the US.

    “He's an artist who challenges idea,” said Ryan Coogler, director of the blockbuster(大片) hit Black Panther, for which Lamar created music. "One big theme in our film of,' What does it mean to be African?' Kendrick in his music is very exactly and directly challenging that question."

    Good artists entertain us, great artists make us think, and exceptional artists help us empathize (感同身受) .

    There are a lot of good, great, even exceptional artists in rock, pop, country, and hip-hop. But only Lamar has a Pulitzer Prize.

    Machines equipped with artificial intelligence (AI) have performed better than human beings in a high-level test of reading comprehension. Two natural language processing tools received higher test scores than humans in recent exams.

    One of the tools is a product of the American software maker Microsoft. The other was created by the Chinese online seller Alibaba Group. The company said that a deep-learning model developed by its Institute of Data Science of Technologies was the first to beat a human score in the reading comprehension test.

    The test is called the Stanford Question Answering Dataset. It was developed by researchers at Stanford University in California. It has over 100,000 questions and answers. They are based on information found in over 500 stories from the Wikipedia website. The answers to all the questions come from the reading material.

    The AI-powered machines were tested on whether they could provide exact answers to the questions after processing large amounts of information.

    Alibaba said its deep neural (神经的) network model received an “Exact Match” score of 82.44 on the Stanford test. Microsoft reported that a team at Microsoft Research Asia had a score of 82.65. It said the human score on the same questions and answers was 82.304. Many research organizations also appeared on the list—all with scores below 82.

    Alibaba said it has already used its reading comprehension model in different parts of its business. For example, the company is using machines to answer many incoming telephone calls from customers. The company says in the future, the technology could enable machines to guide visitors through museums or provide advice to medical patients.

    Microsoft noted that, overall, people are still much better than machines at understanding the complexity and nuances (细微差别) of language.

    Professional athletes pay a high price for their pursuit of excellence and glory. Training to the limit tears muscles and wears out joints. Gymnasts often need hip replacements when barely into middle age. Few footballers make it to the end of their careers with their knees intact.

    But many also run a darker risk: doping—the use of banned athletic performance-enhancing drugs by athletic competitors. The Winter Olympics in Pyeongchang, in South Korea, starts this week in its shadow. Years after whistle-blowers first revealed wholesale (大规模的) doping in Russia, the International Olympic Committee (IOC) at last decided to bar it from taking part. But it has allowed many Russians to compete as individuals. And on the eve of the competition the Court of Arbitration for Sport (CAS) said that 28 others should receive a more tolerant penalty from the IOC, further muffling the anti-doping message.

    Russia's doping is unusual only in its scale and institutional nature. No country or sport is immune. Studies, and an anonymous survey at the World Athletics Championships in 2011, suggest that a third of athletes preparing for big international competitions take banned substances. Yet just 1-2% fail a test each year. Lance Armstrong, a cyclist who won the Tour de France seven times and later admitted to doping all the while, was tested on 250 occasions. The few times he failed, he avoided punishments by claiming he had taken anti-inflammatories (消炎药) for saddle-sores (骑行引起的肌肉酸痛).

    Doping is more sophisticated than when some states used steroids (类固醇) to bulk up athletes. New drugs are designed to be undetectable in a blood or urine sample. Many athletes "blood dope," receiving transfusions or taking a drug that stimulates the production of red blood cells to improve their physical strength. Soviet athletes who were fed steroids suffered a host of serious problems in later life. They were more likely to commit suicide, or to miscarry (流产) or have a disabled child. No one knows what risks those taking new "designer" versions are running. Blood-doping can cause heart attacks; more than a dozen cyclists' deaths have already been linked to it.

    The agencies that set out to stop doping are hugely outclassed. As the argument over punishments on Russia illustrate, they are divided and weak. Most testing is done by national bodies, which may not try very hard to find evidence that would get their own stars banned. The World Anti-Doping Agency (WADA), which oversees them, is packed with officials from national sports federations and the IOC. Their interests are likewise conflicted. Its budget is tiny. The system seems to be designed to look tough but punish only the occasional scapegoat (替罪羊). Honest athletes deserve better.

It's always exciting to receive a letter in the mail. Even today, when the world is digitally connected, receiving an actual letter in your mailbox from a distant land is a great way for children to make new friends. 

The Peaceful Pen Pals Project is a beautiful initiative that combines global connection and self-expression. The project is part of the nonprofit Kids for Peace, founded by Jill McManigal and Danielle Gram in California, in 2006. Letter writing is most certainly hands-on and helps strengthen relationships throughout the world. 

The Peaceful Pen Pals Project is open to all children, ages 2 through 17. To date, there are 1500 children from 17 countries participating in the program. Each child is assigned a pen pal of a similar age. This establishes a point of connection right off the bat for the children and promotes a stronger bond. If the letter writers are in the same grade, they can chat about their schools, teachers, and what they are studying. They can also compare and contrast what different states or countries learn about and how the dynamics of the classroom are, whether socially or academically. 

Children may be more inclined to write about their issues if they feel like they are speaking to a peer in a similar situation. They also write about the local weather, who the letter writer lives with, and their favorite things to do at home. This will give the pen pal a good sense of the writer's home life, and they may relate to certain aspects, such as their parents, the number of siblings, or if they share a room. Although pen pals may live in different countries, they may find common ground according to this information. 

"Hearing first-hand stories from an international pen pal can encourage teens to take someone else's perspective and to think outside of themselves," writes Rebecca Fraser-Thill on Very Well Family. "It can also encourage interest in geography, politics, and history, and promote many key skills, including reciprocation, empathy and mutual concern. "