My parents were in a huge argument, and I was really upset about it. I didn't know who I should talk with about how I was feeling. So I asked Mom to allow me to stay the night at my best friend's house. Though I knew I wouldn't tell her about my parents' situation, I was looking forward to getting out of the house. I was in the middle of packing up my things when suddenly the power went out in the neighborhood. Mom came to tell me that I should stay with my grandpa until the power came back on.

    I was really disappointed because I felt that we did not have much to talk about. But I knew he would be frightened alone in the dark. I went to his room and told him that I'd stay with him until the power was restored. He was quite happy and said, “Great opportunity.”

    “What is it?” I asked.

    “To talk, you and I” he said. “To hold a private little meeting about what we're going to do with your mom and dad, and what we're going to do with ourselves now that we're in the situation we are in.”

    “But we can't do anything about it. Grandpa,” I said, surprised that here was someone with whom I could share my feelings and someone who was in the same “boat” as I was.

    And that's how the most unbelievable friendship between my grandfather and me started. Sitting in the dark, we talked about our feelings and fears of life — from how fast things change to how they sometimes don't change fast enough. That night, because the power went out, I found a new friend, with whom I could safely talk about all my fears and pains, whatever they may be. Suddenly, the lights all came back on. “Well,” he said, “I guess that means you'll want to go now. I really like our talk. I hope the power will go out every few nights!”

    When was the last time you relied on an old-fashioned map to figure out the route to an unfamiliar place? For many, the GPS has revolutionized navigation, making a paper map almost obsolete? So how has this piece of technology developed over its 26 years of existence? On February 14,1989,the first satellite in the US Global Positioning System was sent into space from Cape Canaveral, beginning the start of one of the wonders of the modern world.

    GPS stands for Global Positioning System, which is made of a network of around 30 satellites that move around the earth. The system uses a process called trilateration to find out one's position. By measuring the time it takes for the signal to reach one satellite, the GPS can determine your distance from the satellite, creating a sphere(范围) of possible locations. Measuring your distance from at least three satellites will narrow your location to the place where the three spheres cross one another, to the accuracy(精确) of about less than 1 meter!

    The GPS was first invented during the Cold War by the United States Department of Defense. In 1960, the first system, which was made of just five satellites, was put into place. It was initially created for strictly military(军事的) use; however, in 1983, as a result of faulty navigation technology, a Korean passenger plane mistakenly flew into USSR territory(苏联领土) and was shot down. In order to prevent such bad events, American President Ronald Reagan allowed civilian(民用的) use of the GPS.

    Over the next ten years, the system's accuracy improved as the network was increased to 24 satellites. And during the first Persian Gulf War, the new GPS was finally used by the military. Now scientists use the technology to track animals to better understand their movement and behavior. Parents who may be worried about their children can also use GPS technology to track them.

    Here is an astonishing and significant fact: Mental work alone can't make us tired. 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(毒素)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(情感的)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 a 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.

    Tess was eight years old. Her little brother Andrew was very sick and their parents were completely out of money. She heard Daddy say to her tearful Mother, "Only a miracle can save him now."

    Tess took her money and made her way six blocks to Rexall's Drug Store.

    "And what do you want?" the chemist asked in an annoyed tone of voice. "I'm talking to my brother from Chicago whom I haven't seen for ages."

    "Well, I want to talk to you about my brother," Tess answered back in the same annoyed tone. "He's really sick. He has something bad growing inside his head and my Daddy says only a miracle can save him now. So how much does a miracle cost?"

    "We don't sell miracles here, little girl. I'm sorry but I can't help you," the chemist said, softening a little.

    "Listen, I can help you." The chemist's brother was a well-dressed man. He asked Tess, "What kind of miracle does your brother need?"

    "I don't know," Tess replied. "Mommy says he needs an operation. But my Daddy can't pay for it, so I want to use my money."

    "How much do you have?" asked the man from Chicago. "One dollar and eleven cents," Tess answered. "And it's all the money I have, but I can get some more, if I need to."

    "Well, what a coincidence (巧合)," smiled the man. "A dollar and eleven cents － the exact price of a miracle for your little brother. Take me to where you live. Let's see if 1 have the kind of miracle you need."

    That man was Dr. Carlton Armstrong, a surgeon in neurosurgery (神经外科). The operation was completed without charge and it wasn't long until Andrew was home again and doing well．

    Tess smiled. She knew exactly how much a miracle cost… one dollar and eleven cents… plus the faith of a little child.

    Author Avi, winner of a Newbery Award, a Scott O'Dell Historical Fiction Award, and several Boston Globe-Horn Book Awards, may have seen his first children's book published in 1970, but that doesn't mean he's lost his talent for connecting with young fans.

    The American writer, born in 1937, agrees that getting involved with his readers is one of the key reasons he keeps writing, and that he's been fortunate enough to hear directly from readers about the impact (影响) his books have had. “I have been touched many times by readers who find some special connection between their lives and something I have written: the Danish girl who read something of mine in Danish, and struggled to communicate that in her poor English; the autistic (自闭症的) boy who somehow found something meaningful about my books that reached his own inner life; the women who have told me how important The True Confessions of Charlotte Doyle was to them when growing up."

    Beyond his fans' questions about the characters he's created, the writer's most commonly heard question may be about his own use of the single name “Avi." “As a young adult, I was a reader of French literature, which has that one name tradition: Moliere, Racine, Anouilh, Gide, and so on," he explains. “Avi was given to me by my twin sister when we were very young children, and it stuck. Then my family discouraged me from taking up writing as a career because they considered my writing poor. By using Avi, I was showing my determination to them."

    Although he believes－and has the awards to show－that his writing skills have improved, writing still doesn't come easily to him, despite having over sixty books to his credit. “I never studied writing in any formal sense. I taught myself to write by reading, and by imitating what I was reading," he says.

    The writing task may be tough, but the payoff is big. “To create, share, and support the gift of reading and literature, is to give young people the gift of many worlds, within and without," Avi states.

    Ride-hailing apps and robot cars promise to change how we get around and the effects are already being felt. Traffic in New York is slowing down. Jams are common in Manhattan, especially in its business districts. Daytime traffic in the busiest areas now moves almost 20% more slowly than it did five years ago.

    It seems a place ripe for wide use of ride-hailing apps that, you might think, would reduce some of the jams. However, those apps appear to be making things worse as traffic has slowed in line with the growing popularity of apps such as Uber and Lyft, a study by transport expert Bruce Schaller suggests.

    Over the four years of the study, the number of cars in Manhattan seeking ride-hailing fares increased by 81%. There are now about 68, 000 ride-sharing drivers across New York. That's about five times the number of the yellow cabs licensed to operate there, he found. There are so many drivers, his work suggests, who spend about 45% of their spare time just touring for fares. That is a lot of unused cars blocking a lot of busy streets.

    Simple physics explains why ride-sharing vehicles are causing, not curing jams, said Jarrett Walker, a public transport policy expert who has advised hundreds of cities about moving people.

    "Lots of people are deciding that, 'Oh, public transport is just too much trouble this morning,' or whenever, which causes a shift from it," he told the BBC. "That means moving people from larger vehicles into smaller ones, which means more vehicles to move the same people. Therefore, more traffic."

    Data gathered about ride-sharing drivers illustrates how they contribute to congestion (塞车), said Prof. Christo Wilson, a computer scientist at Northeastern University who has studied the services. "You can look at the traffic pattern for the Uber vehicles and it perfectly matches the peaks for the rush hour and the peak time of a day," he said. They are out there in force at the worst possible times.