Many young students consider their friends as the most important people in their lives. They believe that their family members, especially their parents, don't know them as well as their friends do. In large families, it is often for brothers and sisters to fight with each other and then they can only go to their friends for advice. It is very important for young students to have one good friend or many friends. Even when they are not with their friends, they usually spend a lot of time talking among themselves on the phone. This communication is very important in children's growing up, because friends can discuss something difficult to say to their family members.

    However, parents often try to choose friends for their children. Some parents may even stop their children from meeting their good friends. The question of “choice” is an interesting one.

    Have you ever thought of the following questions?

    Who chooses your friends?

    Do you choose your friends or your friends choose you?

    Have you got a good friend your parents don't like?

    The Canadian red and white maple leaf (枫叶) flag is officially called the National Flag of Canada. The Canadian flag shows a stylized red maple leaf with 11 points on a white background, with red borders down each side. The Canadian flag is twice as long as it is wide. The white square containing the red maple leaf is the same width as the flag.

    The red and the white used in the National Flag of Canada were proclaimed the official colors of Canada in 1921 by King George Ⅴ. Although the maple leaf did not have its official status as a symbol of Canada until the announcement (宣告) of the national flag in 1965, it had historically been used as a Canadian symbol, and was used in 1860 in decorations for the visit of the Prince of Wales to Canada. The 11 points on the maple leaf have no special significance.

    In the early days，the Royal Union Flag，or the Union Jack, was still flown in British North America. In 1925 and again in 1946, the Canadian Prime Minister Mackenzie King tried to get a national flag of Canada adopted, but failed. In 1964，Prime Minister Lester Pearson appointed a 15-member, all-party committee to come up with a design for a new flag. The committee was given six weeks to complete its task.

    The committee studied 2,000 submitted(提交的) designs as well as 3,900 that had been gathered as a result of the 1946 committee's study. Those designs with a chance of being accepted were given to the full committee for further study.

    The suggestion of a red and white single maple leaf design for the Canadian flag came from George Stanley, a professor at the Royal Military College. After a heated discussion, they finally decided on his suggestion.

The Pathfinder

    When we found him, he was a sorry sight. His clothes were torn, his hands bleeding. Before we reached him, we saw him fall. He lay a moment. Then he pulled himself to his feet, walked unsteadily a few yards through the woods and fell again.

    After we got him out, we went back to find the gun that he had thrown down. His tracks showed that for two days he had circled in the forest, within 200 yards of the road. His senses were so dulled by fear and tiredness that he did not hear the cars going by or see the lights at night.

    We found him just in time.

    This man, like others before him, had simply been frightened when he knew he was lost. What had been a near disaster might have turned out as only a pleasant walk, had he made a few preparations before he stepped from the highway or off a known path.

    Whatever sense of direction that a man may have, it's still largely a question of observation. A skilled woodsman always keeps an eye on his surroundings. He notes that the shape of a mountain, the direction water flows through a swamp, and the way a tree leans across a path. With these in mind, he may be turned around many times, but he is seldom lost.

    There are exceptions, of course, and once in a while a man does come across some strange problem that puts him into the “lost” situation. A rainstorm or sudden blizzard may catch him without a compass (指南针) in his pocket. Darkness may find him in a rough area, where travel is dangerous without a light.

    When this happens, the normal first reaction (反应) is the fear of being laughed at as a result of his poor knowledge in the woods. He may also be concerned about the inconvenience that he will cause his friends when he doesn't show up. This false pride may lead him to keep on the move in a false effort to find his way against all difficulties.

    The person who thinks ahead is seldom in great danger. He'll be safe if he observes carefully, thinks ahead, and remains calm.

    People with an impulsive personality refer to those who tend to do things without considering the possible dangers or problems first. According to a new study by researchers at the University of Georgia, such people may be more likely to have food addiction. The study found that people exhibiting impulsive behavior weren't necessarily overweight, but impulsiveness was related to a direct relationship with food, and therefore, less healthy weight.

    Food addiction has been compared to addictive drug use. Studies have linked the dopamine (多巴胺) release that occurs after tasting delicious food to the dopamine release that happens when people consume other addictive substances.

    Impulsive behavior involves several personality traits (特点). Two of these traits, known as negative urgency and lack of perseverance, were particularly associated with food addiction and high BMI (身体质量指数) during the study.

    Negative urgency is characterized by the tendency to behave impulsively when experiencing negative emotions. Some people might drink alcohol or take drugs. For others, it could mean eating to feel better. Lack of perseverance is when a person has a hard time finishing hard or boring tasks. People with a lack of perseverance might have difficulty attempting to change addictive eating behavior, which could also cause obesity.

    “Impulsiveness might be one reason why some people eat in an addictive way despite motivation to lose weight,” said Dr. Ashley Gearhardt, a clinical psychologist. He was involved in developing the Yale Food Addiction Scale in aid of those people. “We are theorizing that if food addiction is really a thing, then our measure, the Yale Food Addiction Scale, should be related to helping control impulsive action,” said Gearhardt.

    Clinical psychologist Dr. James MacKillop, whose lab was conducting the study, believes that therapies used to treat addictive drug behavior could help people who suffer from addictive eating habits.

    “Most of the programs for weight loss at this point focus on the most obvious things, which are clearly diet and exercise,” MacKillop said. “It seems that managing strong desires to eat would naturally fit in with the skills a person would need to eat healthily.”

Life in the Clear

Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between the surface of the ocean and a depth of about 3,300 feet—as far as most light can reach. Most of them are extremely delicate and can be damaged by a simple touch. Sonke Johnsen, a scientist in biology, says, "These animals live through their life alone. They never touch anything unless they're eating it, or unless something is eating them."

And they are as clear as glass. How does an animal become see-through? It's trickier than you might think.

    The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and scatter (散射) light, bouncing it away from its original path. Others absorb light, stopping it dead in its tracks. Both scattering and absorption make an object look different from other objects around it, so you can see it easily.

    But a transparent object doesn't absorb or scatter light, at least not very much. Light can pass through it without bending or stopping. That means a transparent object doesn't look very different from the surrounding air or water. You don't see it you see the things behind it.

    To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments (色素) that absorb specific colors of light. But a transparent animal doesn't have pigments, so its tissues won't absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering.

Animals are built of many different materials—skin, fat, and more—and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see-through. Others build a large, clear mass of non-living jelly-like (果冻状的) material and spread themselves over it.

    Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they're doing it is still unknown. One thing is clear: for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.

    Any foreigner who has tried to learn Chinese can tell how hard it is to master the tones required to speak and understand. And anyone who has tried to learn to play the violin or other instruments can report similar challenges.

    Now researchers have found that people with musical training have an easier time learning Chinese. Writing in the online edition of Nature Neuroscience，researchers from Northwestern University say that both skills draw on the same parts of the brain that help people discover changes in pitch(音调).

    One of the study's authors，Nina Kraus，said the findings suggested that studying music "actually tunes our sensory system" .This means that schools that want children to do well in languages should hesitate before cutting music programs，Dr. Kraus said. She said music training might also help children with language problems.

    Mandarin(普通话)speakers have been shown to have a more complex encoding(编码) of pitch patterns in their brains than English speakers do. This is because in Mandarin and other Asian languages，pitch plays a central role. A single­syllable word can have several meanings depending on how it is intoned.

    For this study，the researchers looked at 20 non­Chinese speaking volunteers，half with no musical background and half who have studied an instrument for at least six years.

    As they were shown a movie，the volunteers also heard an audio tape of the Mandarin word “mi” in three of its meanings: squint，bewilder and rice. The researchers recorded activities in their brain stems to see how well they were processing the sounds. Those with a music background showed much more brain activities in response to the Chinese sounds.

    The lead author of the study，Patrick C.M. Wong，said it might work both ways. It appears that native speakers of tonal languages may do better at learning instruments.