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.

    The world is filled with smart ，educated and gifted people. We meet them every day. A few days ago ，my car was not running well. I pulled it into a garage and the young mechanic fixed it in just a few minutes. He knew what was wrong by simply listening to the engine sound. I was amazed. The sad truth is that great talent is not enough.

    I am constantly shocked at how little talented people earn. I heard the other day that less than 5 percent of Americans earn more than $100，000 a year. A business consultant who specializes in the medical trade told me how many doctors and dentists struggle financially. It was this business consultant （顾问）who gave me the phrase ，“They are one skill away from great wealth.”

    There is an old saying that goes，“JOB means  'Just Over Broke（破产）”. And unfortunately，I would say that the saying applies to millions of people. Because schools do not think financial intelligence is intelligence，most workers “live within their means”. They work and they pay the bills. Instead I recommend that young people seek work for what they will learn ，more than what they will earn.

    When I ask the classes I teach ，“How many of you can cook a better hamburger than McDonald's ？ ” almost all the students raise their hands.I then ask ，“So if most of you can cook a better hamburger ，how come McDonald's makes more money than you？” The answer is obvious: McDonald's is excellent at business systems.The world is filled with talented poor people.They focus on perfecting their skills at building a better hamburger rather than the skills of selling and delivering the hamburger.

    Darwin noted that some human emotional expressions might have started as part of a physiological function: for example, exposing the teeth to bite food. The function, however, took on meaning and became a form of communication which signals anger.

    The same may be true for the animals. Baby monkeys cry for attention. They also cry to signal to an adult that they want to be carried.

    “Chimpanzees do make upset voice when they are being weaned (断奶) by their mothers or have lost their mothers or another individual,” says Anne Pusey, a professor at the University of Minnesota. “They whimper (呜咽) and cry and scream. When we hear these calls, the emotion involved seems obvious. However, they do not weep in the sense of producing tears. I have seen an adolescent male whimpering when he lost sight of his older brother with whom he had been traveling.”

    Babies of many mammalian species, including rats, cry. Moreover, when a baby rat cries, often his mother brings the fallen pup back into the nest. This is probably a straightforward communication, as it is with humans. However, psychologists at the University of Iowa aren't convinced.

    The Iowan researchers can cause the same crying sounds by producing large decreases and then increases in blood flow. The blood flow also goes down when baby rats get cold. Thus, they conclude baby rats cry in the same way that we sneeze. Of course the rat baby could be crying because he's cold and wants his mother to know.

    “All young mammals make cries when separated from their mother,” says Jaak Panksepp, a psychologist at Bowling Green State University. “If you're willing to call this crying, then certainly other animals show this emotional response.” he says, “Some of us take seriously that animals do have emotions.”

    Albert Einsein said," Only a life lived for others is worth living."

How does this job offer sound? You'll need to be available on short notice，including late at night and on weekends. You could be asked to do anything from helping at community events to responding to life-threatening emergencies (sometimes putting your own safety at risk). This job also involves a lot of regular training. Oh, and you won't be paid for any of this. Would you take the job?

    This job might not necessarily appeal to everyone, but if this sounds like an opportunity you'd eagerly accept，then you'd fit right in with Western Australia's 26,000 emergency service volunteers. The emergency services aren't the only industry benefiting from volunteers. Across both Australia and America, between a quarter and half of the population volunteer each year in areas including education, sports, health, religion, and social services.

    What motivates people to volunteer? Yes, volunteers don't get paid. But it doesn't mean people don't get benefits from volunteering. Indeed, research shows there are significant mental health benefits coming with volunteering. It can be a means to make new friends, build new skills or try things out of your comfort zone. It can also be a means to help loved ones. A case is someone close to me who recently lost her husband to a disease. When her husband was admitted to a nursing facility, she decided to volunteer for the patient advocacy committee. She found great support and felt she could make a difference in the lives of the patients. After her husband's passing, she decided to continue volunteering for the committee not only as a way to show gratitude for the great care her husband received but also because she made friends there. She found a way to put her career skills to use for the common good and keep active after retirement.

    There are countless ways to volunteer. No matter how you do it, it is definitely worth every minute you put into it.

    Microsoft announced this week that its facial-recognition system is now more accurate in identifying people of color, touting (吹嘘)its progress at tackling one of the technology's biggest biases (偏见).

    But critics, citing Microsoft's work with Immigration and Customs Enforcement, quickly seized on how that improved technology might be used. The agency contracts with Microsoft for cloud-computing tools that the tech giant says is largely limited to office work but can also include face recognition.

    Columbia University professor Alondra Nelson tweeted, "We must stop confusing 'inclusion' in more 'diverse' surveillance (监管)systems with justice and equality."

    Facial-recognition systems more often misidentify people of color because of a long-running data problem: The massive sets of facial images they train on skew heavily toward white men. A Massachusetts Institute of Technology study this year of the face-recognition systems designed by Microsoft, IBM and the China-based Face++ found that facial-recognition systems consistently giving the wrong gender for famous women of color including Oprah Winfrey, Serena Williams, Michelle Obama and Shirley Chisholm, the first black female member of Congress.

    The companies have responded in recent months by pouring many more photos into the mix, hoping to train the systems to better tell the differences among more than just white faces. IBM said Wednesday it used 1 million facial images, taken from the photo-sharing site Flickr, to build the "world's largest facial data-set" which it will release publicly for other companies to use.

    IBM and Microsoft say that allowed its systems to recognize gender and skin tone with much more precision. Microsoft said its improved system reduced the error rates for darker-skinned men and women by "up to 20 times," and reduced error rates for all women by nine times.

    Those improvements were heralded(宣布)by some for taking aim at the prejudices in a rapidly spreading technology, including potentially reducing the kinds of false positives that could lead police officers misidentify a criminal suspect.

    But others suggested that the technology's increasing accuracy could also make it more marketable. The system should be accurate, "but that's just the beginning, not the end, of their ethical obligation," said David Robinson, managing director of the think tank Upturn.

    At the center of that debate is Microsoft, whose multimillion-dollar contracts with ICE came under fire amid the agency's separation of migrant parents and children at the Mexican border.

    In an open letter to Microsoft chief executive Satya Nadella urging the company to cancel that contract, Microsoft workers pointed to a company blog post in January that said Azure Government would help ICE "accelerate recognition and identification." "We believe that Microsoft must take an ethical stand, and put children and families above profits," the letter said.

    A Microsoft spokesman, pointing to a statement last week from Nadella, said the company's "current cloud engagement" with ICE supports relatively anodyne(温和的)office work such as "mail, calendar, massaging and document management workloads." The company said in a statement that its facial-recognition improvements are "part of our going work to address the industry-wide and societal issues on bias."

    Criticism of face recognition will probably expand as the technology finds its way into more arenas, including airports, stores and schools. The Orlando police department said this week that it would not renew its use of Amazon. com's Rekognition system.

    Companies "have to acknowledge their moral involvement in the downstream use of their technology,"

    Robinson said. "The impulse is that they're going to put a product out there and wash their hands of the consequences. That's unacceptable."

    City trees grow faster and die younger than trees in rural forestry, a new study finds. Over their lifetimes, then, urban trees will likely absorb less CO₂ from the air thah forest trees.

    As we all know, the earth would be freezing or burning hot without CO₂. However, CO₂ is a greenhouse gas, meaning it traps energy from the sun as/heat. That makes temperatures near the ground rise. Human activities, especially the widespread burning-of fossil(化石)fuels, have been sending extra greenhouse gases into the air. This has led to a rise in average temperatures across the globe.

    Studies had shown forests readily absorb CO₂, but there hadn't been much data on whether city trees grow, die and absorb CO₂ at the same rate as forest trees do. So some researchers decided to find out.

    To figure out how quickly trees were growing, researchers tracked their diameters (the width of their trunks) between 2005 and 2014. A tree's diameter increases as it grows, just as a person's waist size increases as they gain weight. About half the weight of a tree is carbon, research has shown. Most of the rest is water. Over the nine years' tracking, the researchers found city trees absorbed four times as much carbon from the air as forest trees. However, they were twice as likely to die. So over the lifetime of each type of tree, forest trees actually absorbed more CO₂.

    City trees grew faster because they had less competition for light from their neighbors. In a forest, trees tend to grow close together, shading their neighbors. Street trees also benefit from higher levels of nitrogen (氮)in rainwater. Nitrogen helps plants grow. Waste gases from gas-burning cars also contain nitrogen, thus enriching city air with nitrogen. Later, rainwater may wash much of it to the ground. Some street trees may also have better access to water than trees in the country because the underground water pipes can leak.