Most animals have little connection with animals of a different kind, unless they hunt them for food. Sometimes, however, two kinds of animals come together in a partnership (伙伴关系) which is good for both of them. You may have noticed some birds sitting on the backs of sheep. This is not because they want a ride, but because they find easy food in the parasites (寄生虫) on sheep. The sheep allow the birds to do so because they remove the cause of discomfort. So although they can manage without each other, they do better together.

    Sometimes an animal has a plant partner. The relationship develops until the two partners cannot manage without each other. This is so in the corals(珊瑚) of the sea. In their skins they have tiny plants which act as “dustmen”, taking some of the waste products from the coral and giving in return oxygen which the animal needs to breathe. If the plants are killed, or are even prevented from receiving light so that they cannot live normally, the corals will die.

    A massive winter storm is expected to begin hitting Massachusetts tonight, dumping up to a foot or more of snow in some areas, while whipping the coast with powerful winds and driving rains, forecasters predict.

    “It's got a little bit of everything,” William Babecock, a meteologist（气象学家）at the National Weather Service in Taunton, said of the post-Christmas storm that brought snowstorm conditions to the Ohio Valley before heading east with its mixed bag of snow, sleet, and rain.

     State Highway Administrator Frank De Paola said more than 4,000 states and snowplows（扫雪车）and salt spreaders were ready to make the roads safer for holiday travelers.

    “MassDOT will be fully staffed and will be ready to handle this,” De Paola said, nothing that the storm, which should bring snow to most of the state except the Cape and Island before turning into rain tomorrow, is Massachusetts' first significant snow storm of this winter season.

    “There have been events where we have had pretty much freezing, icing concerns, which we have treated with chemicals.But this is the first big event that will call for plowing,” he said.

     A high wind watch has been issued for southeastern Massachusetts, including Cape Cod, Forecasters say the wind could reach 60 mph, possibly bringing down power lines.

    In Worcester, some were busy for severer by buying rock salt,shovels and windshield wash,Barrows Hardware president Brain Barrow said.He called the volume（总量）of customers at his Webster Street store very steady on Wednesday morning, “You do get that supermarket effect for sure,”he said of shoppers stocking supplies before a storm.

     There were no flight delays or cancellations at Logan International Airport in Boston as of day,” Right now, everything's running normally.” airport spokesman Richard Walsh said.But Walsh said as the day progressed, travelers should contact their airlines directly to check the status of their flights.

    For most city people, the elevator is an unremarkable machine that inspires none of the enthusiasm or interest that Americans afford trains, jets，and even bicycles. Dr. Christopher Wilk is a member of a small group of elevator experts who consider this a misunderstanding. Without the elevator, they point out, there could be no downtown skyscrapers or tall buildings, and city life as we know it would be impossible. In that sense, they argue，the elevator's role in American history has been no less significant than that of cars. In fact, according to Wilk_? the car and the elevator have been locked in a “secret war” for over a century, with cars making it possible for people to spread horizontally (水平地)，and elevators pushing them toward life in close groups of towering vertical (垂直的)columns.

    If we tend to ignore the significance of elevators, it might be because riding in them tends to be such a brief, boring, and even awkward experience^one that can involve unexpectedly meeting people with whom we have nothing in common, and an unpleasant awareness of the fact that we're hanging from a cable in a long passage.

    In a new book, Lifted, German journalist and cultural studies professor Andreas Bernard directed all his attention to this experience, studying the origins of elevator and its relationship to humankind and finding that riding in an elevator has never been a totally comfortable experience. “After 150 years, we are still not used to it”， Bernard said. “We still have not exactly learned to cope with the mixture of closeness and displeasure.” That mixture, according to Bernard, sets the elevator ride apart from just about every other situation we find ourselves in as we go about our lives.

    Today，as the world's urban population explodes，and cities become more crowded, taller, and more crowded, America's total number of elevators—900,000 at last count, according to Elevator World magazine's “2012 Vertical Transportation Industry”一are a force that's becoming more important than ever. And for the people who really, really love them, it seems like high time that we looked seriously at just what kind of force they are.

    It seems that no one can live a happy life without friendship. While a great number of people expect others to be their friends, they don't give friendship back. That is why some friendships don't last long. To have a friend, you must learn to be one. You must learn to treat your friend the way you want your friend to treat you. Learning to be a good friend means learning three rules: be honest; be generous; be understanding.

    Honesty is where a good friendship starts. Friends must be able to trust one another. If you do not tell the truth, people usually find out. If a friend finds out that you haven't been honest, you may lose your friend's trust. Good friends always depend on one another to speak and act honestly.

    Generosity means sharing and sharing makes a friendship grow. You do not have to give your lunch money or your clothes. Naturally you will want to share your ideas and feelings. These can be very valuable to a friend. They tell your friend what is important to you. By sharing them, you help your friend know better.

    Sooner or later everyone needs understanding and help with each other. Something may go wrong at school. Talking about the problem can make it easier to solve. Turning to a friend can be a first step in solving the problem. So to be a friend you must listen and understand. You must try to put yourself in your friend's place so that you can understand the problem better.

    No two friendships are exactly alike. But all true friendships have three things in common. If you plan to keep your friends, you must practice honesty, generosity and understanding.

    I drove a taxi for extra money east of Toronto thirty years ago. Each time a taxi drove up to the front of the Greenwood Racetrack, a group of local kids would run along the sidewalk angling for position by the passenger door. One lucky kid, or rather, the most aggressive one, would open the passenger door and say "Good luck, Mister!" The man getting out of the cab would vaguely say thanks and throw the kid a quarter. It was a routine everybody knew.

    Throughout the summer, one kid caught my eye. He was bigger than most of all the other kids but pushed away by even the smallest. He never made it but never gave up. One day, his chance arrived. As I was pulling up to the sidewalk, all the kids were pushing for a cab just ahead of mine. The boy saw me and walked toward my taxi. As I positioned the passenger door right beside him, he never paused and opened the passenger door, warmly saying, "Good luck, Mister!"

    But the man neither said thanks nor flipped him a quarter. He pushed him aside so hard that the boy fell on the sidewalk. I knew it hurt him badly. I got out in less than 10 seconds, but the man was gone in the crowd. So I looked for the kid. I decided to give him $20 for the effort. By the time I spotted him he was far up ahead, walking away in the opposite direction through the crowd and his head hanging down. When I got the cab turned around I lost sight of him. I never saw him again. I'd like to find him one day and tell him that if only he had stuck around a little longer I would have given him a whole $20.

    I learned from this kid that when things seem so hopeless that you are ready to give up, it's the time when things are most likely to turn around for you.

Do you know that junk food isn't healthy? Of course you do! Do you eat it anyway? Of course you do! But a new study shows teaching adolescents about the ways food companies fool them into thinking junk food is cool can encourage kids to fight back—by eating healthier.

The pull of junk food can be super-strong. It's designed to be tasty, which makes eating well one of the great health challenges of our time. Everyone from doctors to the government has been trying to handle it. Yet we keep eating junk food.

Professor Christopher Bryan says, "Food companies want you to want junk food." They spend millions of dollars coming up with new ways to promote junk food consumption. They hire scientists to make new junk food almost irresistible. They might do this, for example, by adding more sugar. Rats fed junk food for six weeks will even walk across a floor that gives them electric shocks just to get more of such food.

Food ads often make unhealthy junk food seem healthy by featuring professional athletes, fit-looking pop stars and smiling, active teens. "We thought when the students learned this, it would matter to them," Bryan says. He worked with 8th graders at a Texas school. Half of them got a lesson Bryan created. It focused on the ways junk food is advertised, or marketed. A second group received lessons that focused on health. These lessons informed students junk food is bad, and that foods like apples or carrots are a better choice. The students learned a bad diet can lead to major weight gain, and that being overweight puts people at risk for serious diseases. They also learned how eating well now can keep you healthy when you're older.

After the lessons, the kids in both groups were asked how they felt about junk food. Most didn't have positive feelings about these unhealthy foods.