Here is an astonishing and significant fact：Mental work alone can't make us tire. It sounds absurd．But a few years ago, scientists tried to find out how long the human brain could labor without reaching a stage of fatigue(疲劳). To the amazement of these scientists, they discovered that blood passing through the brain, when it is active, shows no fatigue at all!

    If we took a drop of blood from a day laborer, we would find it full of fatigue toxins (霉素) and fatigue products. But if we took blood from the brain of an Albert Einstein, it would show no fatigue toxins at the end of the day.

    So far as the brain is concerned, it can work as well and swiftly at the end of eight or even twelve hours of effort as at the beginning. The brain is totally tireless. So what makes us tired?

    Some scientists declare that most of our fatigue comes from our mental and emotional (情绪的)attitudes. One of England's most outstanding scientists, J. A. Hadfield, says, “The greater part of the fatigue from which we suffer is of mental origin. In fact, fatigue of purely physical origin is rare. ”Dr. Brill, a famous American scientist, goes even further, He declares, “One hundred percent of the fatigue of sitting worker in good health is due to emotional problems.”

    What kinds of emotions make sitting workers tired? Joy? Satisfaction? No! A feeling of being bored, anger, anxiety, tenseness, worry, a feeling of not being appreciated— those are the emotions that tire sitting workers. Hard work by itself seldom causes fatigue. We get tired because our emotions produce nervousness in the body.

    How would you like to have been born without any ability to feel pain? There are such people. One of them is being studied by doctors at a hospital in New York City. He is a 22-year-old clerk who really does not know the meaning of pain. But he wishes he did.

    Not long ago a packet of matches flared up(骤然烧起) in his hand. Luckily the burn was not serious. It caused large blisters(水泡) but still did not bother him. He said the burn felt like a fly crawling(在……上爬行) on his fingers. It has been the same story as far back as he can remember. He has never had headaches or sore(疼痛的) muscles. Bee stings, cuts and bruises(疼痛的) do not hurt.

    Being free from pain is not as wonderful as you may think. The young man has had to have rotted teeth pulled because he never felt toothache warnings. A sudden attack of appendicitis(阑尾炎) could be deadly. Life without pain is as risky as trying to run a cruise ship without fire alarms.

    An Oceans Vacuum

    There's a collection of plastic trash in the middle of the Pacific Ocean. It's bigger than Texas-and growing. The way to clean it up now is to catch it with nets. That is both costly and slow. Instead, the Ocean Cleanup Project proposes 62-mile-long floating barriers that would use natural currents to trap trash. If next year's trials succeed, a full cleanup operation would aim to start in 2020. It could reduce the trash by 42% over 10 years.

    Easy-On Shoes

    In 2012, Mathew Walzer, a high school student with a disability, sent a note to Nike. “My dream is to go to college,” he wrote, “without having to worry about someone coming to tie my shoes every day.” Nike assigned a design team to the challenge. This year, they came out with their solution: the FlyEase. The basketball shoe can be fastened with one hand. A pair of Nike FlyEase shoes sells for $130.

    An Airport for Drones(无人机)

    As Amazon, Google, and others get ready for drone delivery service, there is one big question: what kinds of home bases will their drones have? Rwanda, in Africa, may have the answer. There, workers will soon start work on three “drone ports”. The goal is to make it easier to transport food, medical supplies, electronics, and other goods through the hilly countryside. Construction is set to be completed in 2020.

    Tom Costello was once afraid of homeless Americans. “I was so afraid that if I saw a homeless person walking down the street, I'd cross the street,” he said.

    That changed seven years ago after his wife, Nancy, a volunteer at a homeless shelter, persuaded him to help with a holiday dinner for shelter residents. Tom remembered going to a store and buying socks for the residents. He knew many of them were in need of clothing.

    At the shelter, Tom said, he dropped a pair of socks into a bag for a woman. She asked him if she could have socks for a friend who wasn't with her that day. He gave her another pair. “She started to cry and told me that nobody had ever given her socks before,” Tom said, “Then she reached out and gave me a hug.” That experience at the shelter helped Tom end his fear of the homeless.

    It also led him to set up a group called “The Joy of Sox.”, which borrows from a name of a popular book. The group collects socks from donors and gives them mostly to shelters in the area where Tom and Nancy live. It has been expanding its reach and provides socks to homeless shelters in 21 states and other three countries now.

    Why socks? Tom explains that some Americans give food, coats and other clothing to shelters. But donating socks is not something most people think about. And, he said, socks are very helpful at keeping people warm, especially in cold weather. A man named Kiwi，who has lived in homeless shelters, said most of the time he could find enough food through shelters and soup kitchens. But socks were much more difficult to get, he noted.

    Benito Juarez, a poor Indian boy, was twelve years old when he left his village home in December 1818.Benito walked forty-one miles to the city of Oaxaca, high in the mountains of Mexico. When he heard the Spanish spoken by the city people, Benito didn't know what they were saying.

    First, Benito became a servant for a wealthy gentleman, Serer Maza. Soon, he went to work for Antonio Salanueva ,a church(教会)librarian. Antonio repaired and copied the library books, keeping them in good shape.  Benito became his helper and his housekeeper. Antonio loved to teach. Benito soon became his student as well as his servant. With the help of Antonio, Benito learned to speak, read, and write Spanish.

    At that time in Mexico, many people believed that Indians were not smart enough to read or learn. Antonio knew that was not true. Indians had been prevented from learning by a lack of schools. The first Spanish missionaries(传教士)who came to Mexico had educated the native people. In fact, churches from Spain had built the first college on the North American continent(大陆)for the Indians. As more Spanish came to Mexico, however, the Indian children were crowded out of the schools.

    Benito was a good and bright student, so Antonio developed a plan for him. In 1821, when Benito was fifteen, Antonio decided to enroll him in a school for boys. Antonio taught Benito what he needed to pass the entrance test for the school.

Benito became a student at the college. His studies were difficult, and he was teased because he was the only Indian student there. He succeeded in spite of these challenges. Later, as the laws changed, Benito was able to attend a public college with other Indians.

    Benito Juarez continued his education and became a lawyer and, much later, the President of Mexico from 1861 to 1872. He led the Mexican people to victory over the French, who tried to rule Mexico, and fought for the rights of Indians. He is one of the great heroes in Mexican history.

WISH YOU WERE MORE CREATIVE?

    I want to ask you a favor. I have a pair of pants. Tell me: How many different ways can I put a pair of pants to use? Now imagine you're an architect. Same question. Now imagine you're Bill Gates. A scuba diver. A medieval knight. You still have the pants. What alternative uses come to mind?

    What you just practiced--the conscious act of "wearing" another self-is an exercise that, according to psychiatrist SriniPillay, MD, is essential to being creative.

    One great irony (讽刺) about our collective addiction to creativity is that we tend to frame it in uncreative ways. That is to say, most of us marry creativity to our concept of self: Either we're "creative" or we aren't, without much of a middle ground. "I'm just not a creative person!" a discouraged student might say in art class, while another might blame her talent at painting for her difficulties in math, making a comment "I'm very right-brained."

    Dr.Pillay, an assistant professor at Harvard University, has spent years overturning these ideas. He believes that the key to unlocking your creative potential is to challenge the stereotyped (陈词滥调的) advice that urges you to "believe in yourself." In fact, you should do the opposite: Believe you are someone else.

    He points to a study showing the impact of stereotype on one's behavior. The authors, psychologists Denis Dumas and Kevin Dunbar, divided their college student subjects into two groups, instructing one group to think of themselves as "eccentric poets" and the other to imagine they were "rigid librarians". The researchers then presented them all with ordinary objects, including a fork, a carrot, and a pair of pants, and asked them to come up with as many different uses as possible for each one. The former group came up with the widest range of ideas, whereas the latter had the fewest.

    These results suggest that creativity is not an individual characteristic but a "product of context and perspective". Everyone can be creative, as long as he or she feels like a creative person.

    Dr. Pillay's work takes this a step further: He argues that simply identifying yourself as creative is less powerful than taking the brave, creative step of imagining you are somebody else. This exercise, which he calls psychological Halloweenism, refers to the conscious action of "wearing" another self. An actor may employ this technique to get into character, but anyone can use it. According to Dr. Pillay, it works because it is an act of conscious unfocus, a collection of brain regions that spring into action when you're not focused on a specific task or thought. Most people spend nearly half of their days in a state of "unfocus." This doesn't make us lazy; it makes us human.

    Imagining yourself in a new situation, or an entirely new identity, never felt so productive. You're making yourself more creative, and you're giving yourself permission to do something you'd otherwise feel guilty about.