To American visitors, Iceland is a very interesting country, partly because it is different in so many ways from he or she is used to seeing at home. There are quite a few things that are not done, or that do not exist on the island—quite a few “No's”.

    There is no pollution, for instance, no dogs are permitted in Reykjavik, the capital. There is no television on Thursdays or during the whole month of July, and only three hours of black and white TV the rest of the time. There is no hard liquor（酒） on Wednesdays and no beer at any time. There is no handguns; only one prison of thirty-five rooms in the whole land—an admirable figure, even for a small country of 313,376 people.

There is no army, air force or navy. There is no tipping（给小费） for anything. There are no large stores open on Saturdays or Sundays. Since Iceland is located just under the Arctic Circle, there is no darkness in summer and no daylight in winter. But thanks to Gulf Stream, the climate is rather mild, with temperatures between 34 degrees and 52 degrees in July.

The rules on television liquor and guns are the result of government decisions. But the absence of pollution is because of in great part the fact that Iceland gets its power from the thousands of hot springs(泉水) that come out of the ground. They provide all the energy needed by the country. In fact, Iceland uses only 3 percent of all its available power.

    Iceland has been described as a democratic（民主的） independent country where more fish are caught and more books published per person than anywhere else in the world. The Icelanders have always felt a particular love for literature. They wrote their first books in the ninth and tenth centuries AD. These works were poems and tales about the kings, heroes, and heroines of Iceland and Norway. At first, the stories were remembered and passed from generation to generation. They were finally written down between 1140 and 1220. The Icelanders have never stopped writing ever since. “Rather shoeless than bookless,” they proudly say.

    Some people make you feel comfortable when they are around. You spend an hour with them and feel you are already close friends. They are always good talkers. Here are several skills that good talkers have in common. If you follow the skills, they'll help you put people at their ease, and make friends with them quickly. {#blank#}1{#/blank#}

    First of all, good talkers ask questions. Almost anyone, no matter how shy he is, will answer a question. One well-known businesswoman says，“At business lunches, I always ask people what they did that morning. {#blank#}2{#/blank#}” From there you can move on to other matters—sometimes to really personal questions. {#blank#}3{#/blank#}

    Second, once good talkers have asked questions, they listen to the answers. Your questions should have a point and help to tell what sort of person you are talking to. And to find out, you really have to listen carefully. Real listening at least means some things. If someone sticks to one topic, you can take it as a fact that he's really interested in it. Real listening also means not just listening to words, but to tones of voice. {#blank#}4{#/blank#}

    Finally, good talkers know well how to “say goodbye”. If you're saying goodbye, you may give him a firm handshake and say, “I've really enjoyed meeting you.” {#blank#}5{#/blank#} Let people know what you feel, and they may walk away, happy and satisfied.

A. It's polite to listen to others with a smile.

B. You'd better change the subject if the voice sounds dull.

C. Don't be afraid to say so if you want to see that person again.

D. Common as the question is, it will get things going.

E. You can become a popular person.

F. And how he answers will let you know how far you can go.

G. These people have something in common.

    My grandmother often said to me, “You can count the number of your true friends on the fingers of one hand.” For a long time I thought this was true. However, I've now discovered my grandmother was only half right. Maybe we do only make a few best friends in our lifetime, but those aren't the only people that we can call friends. There are many different types. Let me tell you about a few of them.

    One type of friends is the type I call the “football mom friend”. My neighbor Sally is a good example. We both have kids who play football in a football club, and someone has to take them to practice and pick them up. Sally and I and two other mothers take turns to do this. We meet sometimes and have tea and talk about what our kids are doing, but those are the only times that we meet each other. I enjoy being with these women, but we don't do anything else together.

    Another type is called the “hobby friend”. That's the person you share an interest or a hobby with. Michael and Cater, who are brothers, are a good example of this type. We're all in a bird watching club. Every few weekends the members of the club go on a trip to watch different kinds of birds. There's nothing romantic about my relationship with Michael and Cater, of course. We just share interest in birds.

    Then there's the “other half of the couple” type of friends. Jim is married to Rose, a friend that I've known since college. When Rose married Jim, I realized that I would have to be Jim's friend if I want to continue to be Rose's. Jim and I don't share so many interests, but we do have a friendly relationship.

    In the story of “The crow and the Pitcher” from Aesop's Fables, a thisty crow (乌鸦)drops stones into a narrow jar to raise the low level of water inside so he can take a drink.

    Now scientists have evidence to back up that story. Crows actually do understand how to make water displacement (移位) work to their advantage, experiments show. The results suggest that the birds are, at least in some aspects, as smart as first-graders.

    Researchers, led by Sarah Jelbert at the University of Auckland in New Zealand, presented six crows with tubes filled with water. Inside the tubes, a worm or piece of meat on a piece of wood was floating, just out of reach of the crow. In front of the tubes, the researchers arranged several rubber erasers that would sink, and some plastic objects that would float. The crows found out that they could drop the erasers into the tubes in order to raise the water level and get their snack.

    However, the birds handled awkwardly in experiments in which they could choose to drop objects in either a wide tube or a narrow one to get a snack, the researchers said. Dropping objects into narrow tube would lift the water level by a greater amount and put the treat within reach after just two drops; while it took around seven drops to raise the snack to the same level in the wide tube. The crows obviously didn't realize this, and most of them went for the wide tube first.

    Previous studies showed that chimps and human children can solve similar tasks. In a 2011 study, chimps and kids found out that they could put water into a tube to reach a peanut that was floating in a small amount of water at the bottom.

    People love cellphones, which is why nine in ten Americans own one. But does heavy use of cellphones pose a risk of cancer? This question has caused controversy for many years. A new study in rats now augments those concerns. Its data linked long-term, intense exposure to radiation from cellphones with an increased risk of cancer in the heart or brain. The results have yet to be confirmed, the authors note.

    Indeed, although the rat study found a link between cellphone radiation and cancer, it offers no clues to why such a link might exist, notes Jonathan Samet. He teaches preventative medicine and directs the Institute for Global Health at the University of Southern California in Los Angeles. Still, he calls the new study's findings “significant”.They could lead to studies researching how cellphone radiation might cause cancer, he says.

    Phone signals are relayed between cell towers and cellphones via radio waves. This radio frequency—or RF—radiation is a type known as non-ionizing (非电离的).Unlike X-rays, non-ionizing radiation does not deposit enough energy into cells to release electrons from atoms or molecules, producing ions. So it tends to be far less harmful than ionizing radiation, such as X-rays. But that does not mean radio waves might not cause harm.

    In very large doses (量) this radiation will heat the body and cause tissue damage. But it's not yet known what much lower RF levels might do, such as those from cellphone use. Five years ago, the World Health Organization's International Agency for Research on Cancer, or IARC, concluded that cellphone use “is possibly carcinogenic (致癌的)”.

    Its conclusion was based on what little research data was available at that time. But notice that IARC was not certain. It said only that phone use might “possibly” cause cancer. So scientists at the National Toxicology Program, or NTP, investigated further.

    Have you ever spent an afternoon in the backyard, maybe grilling or enjoying a basketball game, when suddenly you notice that everything goes quiet? There is an old phrase "calm before the storm", often used in a situation—a quiet period just before a great activity or excitement. According to our own experience, we know there is actually calm before the storm. But what causes this calm? And is it always calm before the storm? Let's hear what scientists have to say.

    A period of calm happens in a particular kind of storm, the simplest kind of storm—a single-cell thunderstorm. In this type of thunderstorm, there is usually only one main updraft, which is warm, damp air and drawn from places near the ground. Storms need warm and damp air as fuel, so they typically draw that air in from surrounding environment. Storms can draw in the air that fit their need from all directions—even from the direction in which the storm is traveling.

    As the warm, damp air is pulled into a storm system, it leaves a low-pressure vacuum (真空) coming after. The rising air meets the cold dry air that has already existed in the storm clouds, thus the temperature of the warm, damp air drops, and the water vapour (水蒸汽) in it changes into tiny drops that are a precondition of rain. These drops accumulate and build on larger particles like dust, until they grow large enough to form raindrops.

    This warm, damp air keeps moving upwards, but it becomes cooler and drier during its trip through cloud. When it reaches the top of the cloud, the air gets spit out (被挤出) at the top. This air is sent rolling out over the big thunderclouds. From there, the air goes down. Warm and dry air is relatively stable, and once it covers a region, that air, in turn, causes the calm before a storm.

    Most thunderstorms, though, don't start with calm. That's because most are actually groups of storms with complex wind patterns. There's so much air moving up and down storm groups that the calm before the storm never happens. Instead, before the storm,让 might be really windy!