“Cleverness is a gift while kindness is a choice. Gifts are easy – they're given after all. Choices can be hard.” –– Jeff Bezos.

    I got the idea to start Amazon 16 years ago. I came across the fact that the Internet usage was growing at 2,300 percent per year. I'd never seen or heard of anything that grew that fast, and the idea of building an online bookstore with millions of titles was very exciting to me. I had just turned 30 years old, and I'd been married for a year. I told my wife MacKenzie that I wanted to quit my job and go to do this crazy thing that probably wouldn't work since most start-ups don't, and I wasn't sure what to expect. MacKenzie told me I should go for it. As a young boy, I'd been a garage inventor. I'd always wanted to be an inventor, and she wanted me to follow my passion.

    I was working at a financial firm in New York City with a bunch of very smart people, and I had a brilliant boss that I much admired. I went to my boss and told him I wanted to start a company selling books on the Internet. He took me on a long walk in Central Park, listened carefully to me, and finally said, “That sounds like a really good idea, but it would be an even better idea for someone who didn't already have a good job.” That logic made some sense to me, and he convinced me to think about it for 48 hours before making a final decision. Seen in that light, it really was a difficult choice, but ultimately, I decided I had to give it a shot. I didn't think I'd regret trying and failing. And I suspected I would always be haunted by a decision to not try at all.

    After much consideration, I took the less safe path to follow my passion, and I'm proud of that choice. For all of us, in the end, we are our choices.

    Movies are a great means of entertainment for many. There are some advantages of watching movies. Comedies, for example, help reduce your blood pressure. Laughter for 15 minutes during a film makes your blood vessels (血管) wider. Besides, when you watch a sad movie, you're more likely to come away from it thinking about loved ones and feeling happy about what you have.

    Watching movies can make you creative. A study shows that young children, who watched the use of magic in Harry Potter, score significantly higher in a creative thinking test than children who watched something else. Moreover, movies are very useful for strengthening people's mental health. They enable people to take time to really relax and temporarily forget about their daily concerns and problems.

    However, watching movies aren't always beneficial. Studies have shown that some people get real pleasure out of being scared by horror movies, but in various ways they may be risking their physical and mental health without even knowing it. When you watch a tense scene in a movie, your heart rate and blood pressure increase. Meanwhile this change in your brain chemistry reminds you of times when you were in a similar state, even if you have no idea you even had those memories. So if something horrible happens to you, being scared again by a movie can unintentionally make you experience it once more.

    Scientists, politicians and parents have debated for decades if being exposed to movie violence leads to actual real-life violence. Overall the answer to that is probably still up in the air, but a new study seems to prove that watching aggression on screen can contribute to being a bully (土霸) in real life, even if it is just in the short term.

    In conclusion, certain movies play a positive role, but not all movies do. It depends completely on the subject of the movie. So it's always advisable to choose the movies concerning something positive.

    For most of my 20 years as a teacher, summer vacation was my time to relax. So why was I standing in the schoolyard of an unfamiliar school, wearing myself out for a summer teaching job? The extra paychecks were nice, but I lacked the energy of my younger colleagues. Like Stella. She was in her early twenties, and made keeping up with the kids look effortless. She reminded me of myself, back when I was a bright-eyed student teacher at Ramona Elementary…

    I'd never forget my first day. I was too full of energy. Nervous energy. My supervising teacher was watching, and I wanted to make a good impression. I asked my third graders to take out their crayons for the day's lesson. All of them obeyed. Except one. A girl with two long, dark braids(辫子). Everyone called her Estrellita, or “little star.” Why was she unprepared for class? I demanded to know.

    “My sister has my crayons,” she said.

    “You should each have your own crayons,” I told her. “That's no excuse.”

    “There are 10 children in my family,” Estrellita said quietly, her big brown eyes never leaving my face. “We have to take turns.”

    I was taken aback. I'd completely misjudged the situation. All day Estrellita's words played on my mind. The next morning I bought a pack of crayons to leave on Estrellita's desk. She was so happy! That experience taught me an important lesson. Every student had a unique set of challenges—it was my mission to help my students overcome them. That mission used to energize(激励 )me.

    Rest was almost over. Stella turned to me and we started chatting. “How long have you been teaching?” she asked. I told her I'd started twenty years before, at Ramona Elementary.

    “I went to school there twenty years ago!” Stella said. I looked at her again, this time really seeing her. Those big brown eyes. That long, dark hair...

    “Did you use to have two long braids?” I said. “We called you Estrellita… ”

    Stella shouted. “ You ! You gave me the crayons!”

She'd become a teacher. To help students like I did. Even doing something that small mattered.

    That summer, I threw myself into teaching with a renewed sense of purpose. Estrellita had taught me a lesson once again.

    One night about nine o'clock, Dr. Eyck, a surgeon, had a phone call from Dr. Haydon at the hospital in Clens Falls. The surgeon was asked to go there at once to operate on a very sick boy who shot himself while playing with a gun.

    The doctor was soon on his way to Clens Falls. It was 60 miles away. And it was snowing heavily in the city. The surgeon thought he could get there before 12 o'clock.

    A few minutes later, the doctor was stopped by a man in an old black coat. Gun in hand, the man ordered the doctor to get out. Then the man drove the car down the road, leaving the doctor in the falling snow.

    It was after 2 o'clock in the morning when the doctor arrived at the hospital in Clens Falls. Dr. Haydon told him that the boy had died an hour before.

    The two doctors walked by the door of the hospital waiting room. There sat the man in the old black coat with his head in his hands.

    "Mr. Cuninghan," said Dr. Haydon to the man, "This is Dr. Eyck. He is the surgeon who walked all the way from Albany to save your boy."

    After the examination, the doctor told my parents my sight would get worse and that I would lose my sight finally. On the way home from hospital, no one said a word. One day, would I only imagine the scenery beyond the glass rather than see it?

    That September, I entered middle school. Most nights I had homework that included an armful of books to read. To keep up with other children, I took great trouble to finish the task. With my nose a couple of inches from the page, I was tired easily. What's worse, after I had read several pages on my own, the words slipped off the page into inky pools.

    However, then I did not have audio books and electric devices like kids do now. Instead, Mum volunteered to read out loud. Mum worked part-time, cleaned the house, cooked and spent time with Grandma. In spite of being so busy, she showed up in my room like clockwork. She put on her reading glasses. Mum always thought those glasses made her look old. To me, she looked like a teacher.

    In my room, Mum's voice raced with the ticking of the clock. Being forced to focus on listening, I found a way to keep my marks up and compete with the other kids. When the teacher asked a question, I raised my hand with confidence. Teachers praised me for having a good memory. Reading removed my fear for my failing sight, reading also made me curious about other people's challenges and how they managed. Though I could not use my eyes to fix on each passage, my mind lit up with every new book.

    True to what the doctor said, the worst came, but thanks to Mum, my sense of hearing now allows me to “see”. This was the most precious gift from a mother to her child.

    Anyone watching the autumn sky knows that migrating birds fly in a V formation, but scientists have long debated why. A new study finds that these big－winged birds carefully position their wingtips and flap(拍动) at the same rate, probably to catch the upward movement of air and save energy during flight.

    There are two reasons birds might fly in a V formation: It may make flight easier, or they're simply following the leader. Squadrons(中 队) of planes can save fuel by flying in a V formation, and many scientists suspect that migrating birds do the same. Models that treated flapping birds like fixed－wing airplanes show that they probably save energy by drafting off each other, but currents created by airplanes are far more stable than those coming off of birds.

    Just as aerodynamic(气动力) calculations would predict, the birds positioned themselves to fly just behind and to the side of the bird in front, timing their wing flaps to catch the uplifting eddies(涡流). When a bird flew directly behind another, the timing of the flapping reversed(相反) so that it could minimize the effects of the downdraft coming off the back of the bird's body. “We didn't think this was possible,” Usherwood says, considering that the difficult achievement requires careful flight and incredible awareness of one's neighbors. “Perhaps these big V formation birds can be thought of quite like an airplane with wings that go up and down.”

    The findings likely apply to other long－winged birds, such as pelicans and geese, Usherwood says. Smaller birds create more complex wakes(尾波) that would make drafting too difficult. The researchers did not attempt to calculate the birds' energy savings because the necessary physiological measurements would be too invasive for an endangered species. Previous studies show that birds can use 20% to 30% less energy while flying in a V.

    Scientists do not know how the birds find that aerodynamic sweet spot, but they suspect that the animals line themselves up either by sight or by sensing air currents through their feathers. In future studies, the researchers will switch to more common birds, such as pigeons or geese. They plan to investigate how the animals decide who sets the course and the pace, and whether a mistake made by the leader can ripple through the rest of the flock to cause traffic jams.