Neither rain nor snow nor the dark of night can separate Tennessee postal carrier “Mailman Mike” from his 4-and-a-half-year-old friend Carter Lawson – or keep them from their appointments.

    For the past nine months, the two have teamed up every day in the preschooler's Knoxville neighborhood for a few minutes of delivering mail together and chatting with fellow neighbors. Lawson wants to be a mail carrier when he grows up, and in an inspiring story, his mom told us how mailman Mike Crenshaw has been a role model to her son. “Anyone could just be like 'Go away, kid', but Mike has really gone out of his way to talk with Carter,” said Cassie Lawson of the United States Postal Service carrier. Little Carter even got his own uniform to match Mike's. “It's been really cute. I just couldn't believe he got a full mailman's costume,” the postal service employee said.

    “Every letter carrier has stops he looks forward to and this is the one I look forward to every day,” said Mike. “He's the end of my day, and the best part of my day. Not because it's the end, but because he's such a cute little guy.”

    The man and the little boy's connection isn't a surprise to Fredric Rolando, president of the National Association of Letter Carriers. “Kids respond to mailmen because letter carriers are a friendly, uniformed part of the neighborhood who bring something to their house every day, and are someone they come to recognize and trust,” Rolando said. “It's the same for the elderly, but in addition, letter carriers may be the only person they communicate with all day.”

    The researchers say a person loses two months for every kilogram overweight they are— and seven years for smoking a packet of cigarettes a day.

    Unusually, the Edinburgh university team found their answers by analysing differences in people's genetic code or DNA. Finally they think it will show new ways of helping us to live longer.

    The group used the genetic code of more than 600, 000 people who are taking part in a natural experiment. If someone smokes, drinks, drops out of school and is overweight, it can be difficult to identify the impact of one specific unhealthy behavior.

    Instead, the researchers turned to the natural experiment. Some people carry mutations(变异) in their DNA that increase(食欲) or make them more likely to put on weight, so researchers were able to compare those programmed to eat more with those who were not. The research team also found specific mutations in human DNA that alter lifespan (寿命).

    Mutations in a gene (a set of instructions in DNA) that is involved in running the immune system could add seven months of life on average.

    People with a mutation that increased levels of bad cholesterol knocked eight months off lifespan.

    A rare mutation in a gene—APOE—linked to dementia reduced lifespan by 11 months.

    And one that made smoking more appealing cut lives by five months.

    Dr Joshi says that while genes do influence lifespan, “you've got even more influence” through the choices you make. Dr Joshi said, “We hope to discover genes affecting lifespan to give us new information about ageing and construct treatment tor ageing.”

    There are also some disease mutations that clearly affect lifespan and to destructive effect, such as the Huntington's gene. People with Huntington's often die in their 20s.

    However, in order to follow people until the end of their lives, many of the people studied were born before 1940.

    In the mid-nineteenth century, as iceboxes became increasingly common in American homes, there were efforts to find cheaper and more reliable sources of ice. In the eighteen-thirties, scientists discovered a way to make ice, which is similar to how a refrigerator works. In 1860, there were four artificial-ice plants in the United States; in 1889, there were about two hundred; by 1909, there were two thousand. Ice now came from factories, not ponds, and it was turned out in three-hundred-pound blocks by lowering steel cans of pure water into tanks of refrigerated salted water. Kept below thirty-two degrees, the salted water did not freeze, but the water in the cans did. Those cans were then lifted from the tank, and the ice was taken out of them.

    The ice blocks were delivered to home users, and to the fishing and chemical industries. On the railroads, trains carrying fruit and vegetables had cars at each end filled with blocks of ice. It was a growing industry.

    The great trade began to fall away in the middle years of the twentieth century. The railroad business shrank, and, in the immediate postwar period, block ice lost out to home refrigerators and then to small commercial ice machines. By the nineteen-sixties, things looked very dark. “It was scary,” Dan Ditmar, an ice expert in San Antonito, told me. “Your biggest customers were cafeterias and country clubs, and you'd go out there and they'd say, 'We don't need you anymore; we've got ice machines.'”

    Then the companies that survived the slump（a slump is a period when there is a reduction in business）began investing（投资）in newly developed ice-cube machines, and by the late sixties American ice was becoming a packaged-ice business. And packaged ice was exactly what the country needed. These were years of increased leisure time—more barbecues, more cars, and more houses by the lake. “Things exploded in the nineteen-seventies, Paul Handler said. Ice cubes evolved. They became hugely popular^ shoveled（铲）here and there into picnic coolers and fast-foof sodas. They became noisier.

    The National Day holiday is a great opportunity to do something a little different. Many people use the National Day for a getaway, a short trip to leave the stress of their everyday lives behind and explore, learn, or relax.

    Hotel Romance

    Many hotels and resorts feature something special to start the getaway, such as champagne, flowers, or a fruit basket in the room on arrival. Getaway packages usually include a room with something special, a heart shaped bed, for example. Additional benefits could be room service meals or other private dining, plus tickets or discounts for local attractions.

    Visit a Spa

    Spa getaways can take place at a location that focuses only on spa services or at a hotel that offers a spa as one of its features. Some spas emphasize treatments fit for their geographic area or a local attraction. A spa in a grape growing region might provide grape juice masks, or a hotel near a hot spring could offer mineral baths. Most spas offer a range of massage, health and beauty treatments, so a spa getaway can be relaxing with other benefits.

    Learn a Skill

    The National Day holiday may not be enough time to become an expert at something new, but it provides a way for people to begin their explorations. Some organizations offer intensive courses that last five or six days. People with special interests can get away from their routines while learning such things as how to make beer, speak a new language, or take better photos.

    Help Others

    Some organizations cooperate with businesses to have accommodations and activities for short-term volunteers. Most volunteer vacations involve ecology friendly or charity activities. A volunteer getaway is a way to relieve stress and help others at the same time.

    Stay in a National Park

    For those who want to relax in a rural environment, a national park fits the bill. Most national parks provide camping areas for tents and trailers. Several have cabins within the parks available to rent. A getaway to a national park provides privacy, stress relief, and the time to get to know some important natural resources.

    People traveling long distances frequently have to decide whether they would prefer to go by land, sea, or air. Hardly can anyone positively enjoy sitting in a train for more than a few hours. Train carriages soon get crowded. Reading is only a partial solution, for the monotonous(单调的) rhythm of the wheels clicking on the rails soon makes you sleep. During the day, sleep comes in snatches. While at night you rarely manage to sleep. Inevitably you arrive at your destination almost exhausted.

    Long car journey are even less pleasant, for it is quite impossible even to read. On motorways you can, at least, travel fairly safely at high speed, but more often than not, the greater span of the journey is spent on narrow, uneven roads which are crowded with traffic.

    By comparison, trips by sea offer a great variety of civilized comforts. You can stretch your legs on the broad decks, play games, swim, meet interesting people and enjoy good food-always assuming, of course, that the sea is calm. If it is not and you are likely to get seasick, no form of transport could be worse. Even if you travel in ideal weather, sea journeys take a long time. Relatively few people are prepared to sacrifice up to a third of their holidays for the pleasure of traveling on a ship.

    Airplanes have the reputation of being dangerous and a little expensive. But nothing can match them for speed and comfort. Traveling at a height of 30,000 feet and at over 500 miles an hour is a pleasant experience. For a few hours, you settle back in a deep armchair to enjoy the flight. The real relaxation can be a free film show and some other services. An airplane also offers you an unusual and breathtaking view of the world. You really see the shape of the land. If the landscape is hidden from the view, you can enjoy the extraordinary sight of unbroken cloud plains that stretch on for miles before you, while the sun shines brilliantly in a clear sky. The journey is so smooth that there is nothing to prevent you from reading or sleeping. However you decide to spend your time, one thing is certain: you will arrive at your destination fresh and untired.

Mark and his brother Jason both were looking at the shining new computer enviously. Jason was determined not to go against their father's wishes but Mark was more adventurous than his brother. He loved experimenting and his aim was to become a scientist like his father.

"Dad will be really mad if he finds out you've been playing with his new computer." said, "He told us not to touch it."

"He won't find out," Mark said, "I'll just have a quick look and shut it down."

Mark had been scolded before for touching his father's equipment. But his curiosity was difficult to control and this new computer really puzzled him.

It was a strange-looking machine — one his dad had brought home from the laboratory where he worked. "It's an experimental model." his father had explained, "so don't touch it under any circumstances." But his father's warning only served to make Mark more curious. Without any further thought, Mark turned on the power switch. The computer burst into life and seconds later the screen turned into colours, shifting and changing, and then two big white words appeared in the centre of the screen: "SPACE TRANSPORTER."

"Yes!" Mark cried excitedly. "It's a computer game. I knew it! Dad's only been pretending to work. He's really been playing games instead!" A new message appeared on the screen:

"ENTER NAMES

VOYAGER 1:…

VOYAGER 2:…

Mark's fingers flew across the keyboard as he typed in both of their names.

"INPUT ACCEPTED. START TRANSPORT PROGRAM. AUTO-RETRIEVE INITIATED. "

The screen turned even brighter and a noise suddenly rose in volume.

"I think we'd better shut it off, Mark," Jason yelled, reaching for the power switch. He was really frightened.

But his hand never reached the switch. A single beam of dazzling white light burst out of the computer screen, wrapping the boys in its glow, until they themselves seemed to be glowing. Then it died down just as suddenly as it had burst into life. And the boys were no longer there. On the screen, the letters changed:

"TRANSPORT SUCCESSFUL. DESTINATION: MARS. RETRIEVE DATE: 2025."