Miss Parker taught physics in a New York school. Last month she explained to one of her classes about sound ,and she decided to test them to see how successful she had been in her explanation. She said to them, “Now I have a brother in Los Angeles. If I was calling him on the phone and at the same time you were 75 feet away, listening to me from across the street, which of you would hear what I said earlier, my brother or you and for what reason?”

    Tom at once answered, “Your brother. Because electricity travels faster than sound waves.”“That's every good,” Miss Parker answered; but then one of the girls raised her hand, and Miss Parker said.“Yes, Kate.”

    “I disagree,” Kate said.“Your brother would hear you earlier because when it's 11 o'clock here it's only 8 o'clock in Los Angeles.”

    Dyslexia(失读症) is a learning disorder, it interferes with the ability to recognise words, and for some readers to understand what they have read.

    Experts say dyslexia affects about five to ten percent of the population of the United State. Researchers have long known that people with dyslexia write or read words and letters backwards in the wrong order.

    But a new study shows that people with dyslexia may have trouble redirecting(重新传入) their attention between senses, from seeing something to hearing something. The study suggests something that might help dyslexic people learn more quickly — play video games.

    Vanessa Harrar of Britain's University of Oxford led the study. She reported the findings in the journal Current Biology. The study suggests that dyslexic people may have trouble moving quickly from what they read to what they hear. Doctor Harrar calls this a "sluggish shifting of attention across the senses."

    "So, if you are trying to read something and then trying to listen to somebody who's reading aloud and you're trying to follow along with what they are reading -- they have to switch their attention from hearing what they are saying to looking at the piece of paper and back again. So we found they have quite sluggish shifting of attention across the senses," said Harrar.

    In the study, Doctor Harrar tested 17 people with dyslexia, and 19 others without reading problems. The volunteers were asked to push a button as quickly as possible when they heard a sound, saw a light or experienced both together. Doctor Harrar compared the speed of their reactions.

    She found that people with dyslexia were just as fast as the others when they saw only a picture or heard only a sound. But the dyslexics had a slower reaction time when they heard a sound and saw a picture at the same time.

    Doctor Harrar feels like playing action video games could help dyslexic people shift from seeing to hearing more quickly. She adds that images in video games force the eyes to move and focus quickly.

    "Video game types of things pop out of here and there, they move your eyes around the screen quite quickly in response to things quite quickly, and the more you play a video game the faster you get that kind of thing. So, the video game is really training the attention system to move quickly," said Harrar.

    The study also shows that dyslexic people have the most difficulty going between what they saw and what they heard, this may have an effect on how dyslexic children are taught how to read.

    When children learn the alphabet, they usually see the letter first and then hear the sound, or they see and hear the letter at the same time. The study shows that dyslexics might learn more quickly if they hear the sound of a letter or word first before seeing it.

    It may sound strange, but cutting down a real tree for Christmas is actually greener than going with the artificial kind, one scientist says.

    “It is a little confusing to people,” said Clint Springer, a biologist at Saint Joseph's University in Philadelphia. Because of concerns over deforestation（砍伐森林）around the world, many people naturally worry that buying a real tree might contribute to that problem. But most Christmas trees for sale these days are grown not in the forest but on tree farms for the purpose of being cut.

    Moreover, from the viewpoint of greenhouse gases, real trees are “the obvious choice”. Live trees actively release oxygen as they grow, and meanwhile remove carbon dioxide from the atmosphere. After they have been cut and Christmas is over, they're usually cut into smaller pieces for mulch（覆盖物）. As mulch, the bits of trees very slowly release carbon dioxide back into the atmosphere. So in the end, a real Christmas tree is carbon neutral, putting the same amount of carbon dioxide back into the air as it took out (although much more slowly).

    The tree farms that grow the trees also replant after the trees are cut.  Artificial trees, on the other hand, don't come out even in the carbon balance. Petroleum（石油）is used to make the plastics in artificial trees and lots of carbon dioxide-creating energy is required to make and transport them. Because these trees just end up in the places where waste is buried under the ground after use, “those greenhouse gases are lost forever,” Springer said.

    Antarctica, with its seemingly endless icy beauty, is one place where one look is worth a thousand words. My own dream to see it came true last January when I joined the sixth exploration crew(考查队) of the China National Marine Bureau. We spent 10 days connecting flights to reach our goal, but finally arrived at the Great Wall Station on Antarctica on the eve of Chinese New Year.

    There are only two seasons in Antarctica: winter and summer. You get polar nights in winter and polar days in summer. Day is longer than night in summer, and the temperature often reaches below zero. Luckily, there are no snowstorms in summer, which makes it the best season to travel. What I imagined before starting for Antarctica was a world of ice, storms, endless cold and loneliness. When I stopped on Antarctica for the first time, however, I saw rich, energetic and beautiful scenery that was beyond anything I had imagined.

    We only spent 11 days at the South Pole, but every minute was spent taking pictures and losing our heart to the wonderland. Beauty enveloped us as we watched the world around us. The mountains, oceans, ice, snow, sky, earth and people all seemed to have their own stories.

    Rocks from Antarctica are considered valuable. Unfortunately, I didn't bring one back. However, my heavy bags full of films are certainly worth that. It is in these pictures that the true Antarctica comes alive.

    Give yourself a test. Which way is the wind blowing? How many kinds of wildflowers can be seen from your front door? If your awareness is as sharp as it could be, you'll have no trouble answering these questions.

    Most of us observed much more as children than we do as adults. A child's day is filled with fascination, newness and wonder. Curiosity gave us all a natural awareness. But distinctions that were sharp to us as children become unclear; we are numb(麻木的）to new stimulation(刺激), new ideas. Relearning the art of seeing the world around us is quite simple, although it takes practice and requires breaking some bad habits.

    The first step in awakening senses is to stop predicting what we are going to see and feel before it occurs. This blocks awareness. One chilly night when I was hiking in the Rocky Mountains with some students, I mentioned that we were going to cross a mountain stream. The students began complaining about how cold it would be. We reached the stream, and they unwillingly walked ahead. They were almost knee-deep when they realized it was a hot spring. Later they all admitted they'd felt cold water at first.

    Another block to awareness is the obsession(痴迷) many of us have with naming things. I saw bird watchers who spotted a bird, immediately looked it up in field guides, and said, a "ruby-crowned kinglet" and checked it off. They no longer paid attention to the bird and never learned what it was doing.

    The pressures of "time" and "destination" are further blocks to awareness. I encountered many hikers who were headed to a distant camp-ground with just enough time to get there before dark. It seldom occurred to them to wander a bit, to take a moment to see what's around them. I asked them what they'd seen. "Oh, a few birds," they said. They seemed bent on their destinations.

    Nature seems to unfold to people who watch and wait. Next time you take a walk, no matter where it is, take in all the sights, sounds and sensations. Wander in this frame of mind and you will open a new dimension to your life.

    A picture speaks a thousand words. And with over a thousand emoji pictures to represent our words, who needs to speak or write any more? According to Professor Vyv Evans of Bangor University, emoji is the UK's fastest-growing language in history. These little electronic pictures started life in Japanese mobile phones in the 1990s and are now hugely popular. They have inspired fashion, like the real-life dress copied from the dancing lady emoji, and are even recognized as art! In New York's Museum of Modern Art you can now see the first set of the 176 original emojis.

    Why do we love them so much? They allow us to personalize text and have fun as we express ourselves, make people laugh and be creative in how we use them. UK teenagers also told us they really appreciated the fact that emojis are quick and easy.

    People have their favourite emojis. In the UK, the most used emojis are ' face with tears ofjoy', ' face blowing a kiss' and 'Iove heart'. Maybe (with emojis at least) the British are more fun and romantic than people think! Companies such as McDonalds have also tried to use people's love of emojis to make advertisement. They used a series of emojis to tell a story of a disappointing day given a happy ending by a visit to McDonalds. Unluckily for McDonalds, most people added the vomiting(呕吐) emoji to the blank space after the story.

    What is the future of emoji? Is emoji developing so rapidly that it will soon compete with English as a global language? Or is technology changing so fast that emoji will soon be forgotten when the next big thing comes along? It is hard to say and even technology and language experts are divided on the subject.

    What do you think? Keep your eyes open for new developments!