The Renaissance，considered by modern scholars to have been the time between 1,300 and 1,600，was a period of European history when many new inventions and beliefs came into being.

    The Renaissance is traced back to rich Italian cities such as Florence，Milan，and Venice.In these cities businessmen started to spend their extra money on things like painting and education，and to consider new techniques of banking and systems of government.A new type of scholar，the humanist(人文主义者)arose.Humanism was concerned with humankind and culture.Latin and Greek，literature and philosophy，music and mathematics were among the subjects humanists studied.

    The Renaissance gave rise to new forms of painting and  sculpture.During  the  Renaissance，artists were no longer regarded as mere artisans(工匠)．Many artists drew on mathematics in order to become more accurate in their measurements(度量)and to make sure an object was presented in realistic proportions.They also studied the way light hits objects and the ways our eyes perceive it.A new kind of paint，called oil paint，was invented.

    The Renaissance affected all of the society.Many people became interested in politics，and the world outside their towns.They became explorers，businessmen，etc.The effect on religion was especially strong.In the Middle Ages people were primarily concerned with serving the church and getting to heaven.But the increase in arts  and education gave  people things to look forward to in life，and made them lose interest in the church.

    The  Renaissance  produced  many  great minds.Leonardo da Vinci was one of the greatest，although he was not regarded that way at the time.Among his many works of art were Mona Lisa and The Last Supper.He is also regarded as a great inventor，and is credited for coming up with the idea of the helicopter.

Father's Day

    The United States is one of the few countries in the world that has an official day on which fathers are honored by their children. On the third Sunday in June, fathers all across the United States are given presents, treated to dinner or otherwise made to feel special.

    However, the idea for creating a day for children to honor their fathers began in Spokane, Washington. A woman by the name of Sonora Smart Dodd thought of the idea for Father's Day while listening to a Mother's Day sermon in 1909. Having been raised by her father, Henry Jackson Smart, after her mother died, Sonora wanted her father to know how special he was to her. It was her father that made all the parental sacrifices and was, in the eyes of his daughter, a selfless and loving man. Sonora's father was born in June, so she chose to hold the first Father's Day celebration in Spikane, Washington on the 19th of June, 1910.

    In 1924 President Calvin Coolidge declared the third Sunday in June as Father's Day. Roses are the Father's Day flowers: red to be worn for a living father and white if the father has died.

    When children can't visit their fathers or take them out to dinner, they send a greeting card. Traditionally, fathers prefer greeting cards that are not too sentimental. Most greeting cards are too special so fathers laugh when they open them. Some give heartfelt thanks for being there whenever the child needed Dad.

    People who multitask all the time may be the worst at doing two things at once, a new research suggests. The findings, based on performances and self-evaluation by about 275 college students, indicate that many people multitask not out of a desire to increase productivity, but because they are easily distracted and can't focus on one activity. And “those people turn out to be the worst at handling different things,” said David Sanbonmatsu, a psychologist at the University of Utah.

    Sanbonmatsu and his colleagues gave the students a set of tests and asked them to report how often they multitasked, how good they thought they were at it, and how sensation-seeking (寻求刺激) or imperative (冲动) they were. They then evaluated the participants' multitasking ability with a tricky mental task that required the students to do simple mathematical calculations while remembering a set of letters.

    Not surprisingly, the scientists said, most people thought they were better than average at multitasking, and those who thought they were better at it were more likely to report using a cellphone while driving or viewing multiple kinds of media at once. But those who frequently deal with many things at the same time were found to perform the worst at the actual multitasking test. They also were more likely to admit to sensation-seeking and impulsive behavior, which connects with how easily people get bored and distracted.

     “People multitask not because it's going to lead to greater productivity, but because they're distractible, and they get sucked into things that are not as important.” Sanbonmatsu said.

    Adam Gazzaley, a researcher at the University of California, San Francisco, who was not a member of the research group, said one limitation of the study was that it couldn't find out whether people who start out less focused tend toward multitasking or whether people's recognizing and understanding abilities change as a result of multitasking.

    The findings do suggest, however, why the sensation-seeker who multitask the most may enjoy risky distracted driving. “People who are multitasking are generally less sensitive to risky situations.” said Paul Atchley, another researcher not in the group. “This may partly explain why people go in for these situations even though they're dangerous.”

    When asked how technology might improve the lives of people with vision impairments (视力障碍), Joann Becker presented a misleadingly simple challenge. “Well,” the vision impairments tech specialist recalls saying. “I'd like to be able to find my bus slop through Be My Eyes”.

    Be My Eyes, which went live in 2015, establishes a direct video connection between visually impaired users and sighted volunteers. The assumption is simple: Many people who are blind don't need any actual assistance in completing their daily tasks, but merely need a little help.

    A sighted volunteer might be asked to help identify which of two cans contains tomatoes. In this case, the visually impaired user can cook a meal just fine on his/her own-all he/she needs is a quick confirmation that he/she has the correct can. The model appears to be working; more than 540,000 volunteers and nearly 40,000 people with low vision are registered on the app.

    “An elderly woman can now help a visually impaired technician set up his computer,” says founder Hans Wiberg, who has very low vision. “She doesn't need to know a thing about computers. She only needs to read what is presented on the screen. Then he can do the rest.”

    Early assistive technology centered on dedicated devices (专用设备), because of the niche market (缝隙市场), which sold for hundreds or even thousands of dollars. But the smartphone, multipurpose and near-universal, has completely changed the economy of scale.

    “There are larger market forces driving high-powered computation, high-quality engineering and high-quality battery management in the smartphone market than those in a specialty product,” says Aaron Steinfeld, a research professor at the Robotics Institute at Carnegie Mellon University.

    “The reality is, most sighted people don't know somebody who is blind.” Becker says. “They think the solutions that a blind person needs arc far more expansive, it turns out, they need to be. I think these apps are enabling sighted people to see that blind people just need some simple clues to help them do any number of things in their lives.”

    Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures 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, 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.

There has been tremendous concern recently over misinformation on social media. This concern is quite justifiable, as the consequences of believing false information are greatly affecting the individual and collective health.

Many people tend to fall for misinformation they encounter online. There is one influential explanation for this phenomenon. As the thinking goes, someone, who possesses very limited skills in finding and consuming digital content, creating digital content, and communicating it, is likely to have difficulty recognizing false information and thus is more vulnerable to believing false information. As a result, these less digitally literate people may play a significant part in the spread of misinformation.

This argument sounds perfectly plausible. Yet very little research has actually investigated the link between digital literacy and the vulnerability to believing false information. There's even less understanding of the potential link between digital literacy and what people share on social media. A group of MIT researchers explored these potential associations by surveying 1,341 Americans.

In the experiment, the researchers first showed the participants two dozen news headlines about politics, half of which were accurate, and half of which were false. In the second phase, they included a series of tests: having the participants report their familiarity with various Internet-related terms and answer questions about how social media platforms decide what to show in their newsfeeds. At last, the participants were required to assess the accuracy of a set of headlines and point out their likelihood of sharing each headline on social media.

The researchers found "clear evidence" that digital literacy was a strong predictor of accuracy discernment (识别能力). However, the results were "strikingly different" regarding sharing discernment. Digitally literate subjects were just as likely to share inaccurate information. Most surprisingly, even people with high digital literacy were not immune from clicking "share" for false news.

This sounds odd. Although most people don't want to spread misinformation, social media is distracting: people are scrolling quickly, and their attention is drawn to social validation (社会认知度), such as how many likes their posts will get. So make sure a certain post is accurate before you click the "share" button.