Rick Garcia is going to play outside with his friends. He is taking out his reliever inhaler (缓解物吸入器) and taking two puffs (吸). Five minutes later, he's on the field with his friends, running after a soccer ball. Rick has asthma (哮喘), but he knows how to control it.

    Asthma is a lung disease. A person with asthma may cough or suffer from shortness of breath. Asthma can begin at any age. Childhood asthma, often beginning when a child is younger than 10 years old, is one of the most common childhood diseases. Doctors report that the number of young people with asthma is increasing. It is the number one cause of absence from school. If parents have asthma, their children are more likely to develop the disease. Children in homes where an adult smokes are more at risk.

    It is important to find out the triggers for asthma. As we know, dust, pollen, or animals often make people suffer from asthma. Once a child learns the triggers, he can help prevent future attacks. About half of all children outgrow asthma and then asthma attacks stop when they are teenagers. However, many people live with the disease into adulthood.

    Children often take control drugs once or twice a day to help prevent asthma attacks, if a child begins to have an asthma attack, a quick-relief drug is also necessary. This is often an inhaler. School-aged children usually carry their inhalers with them. This medication works quickly and children begin to breathe more easily in a few minutes. If a child has a serious asthma attack, he may need full-time care at a hospital or a doctor's office.

    National Rankings: Best High Schools

    The U.S. News rankings include data on more than 22,000 public high schools in 50 states and the District of Columbia. Schools were awarded gold, silver or bronze medals based on their performance on state assessments and how well they prepare students for college.

    About the Awards

    Gold—Top 500 Schools based on highest college readiness.

    Silver—High-performing schools based on lower college readiness.

    Bronze—High-performing schools based on state exam performance,  listed alphabetically.

    Award Distribution

    Gold 2.4%

    Silver 10.3%

    Bronze 16.8%

    No Medal 70.5%

    HOW We Determine the Awards

    STEP 1 Students perform better than expected in their state.

    We looked at reading and math results for students on each state's proficiency(水平) tests and then factored in the percentage of economically disadvantaged students, who tend to score lower.

    STEP 2 Disadvantaged students perform better than state average.

    We compared each school's math and reading proficiency rates for disadvantaged students--black, Hispanic and low-income—with the state wide results for these student groups and then selected schools that were performing better than their state averages.

    STEP 3 Student graduation rates meet or are greater than a national standard.

    We left out schools from consideration if their graduation rates were lower than 75 percent--a starting point that is higher than a federal law that requires states to give extra resources to schools below 67 percent.

    STEP 4 Students are prepared for college-level coursework.

    We calculated a College Readiness Index,which is based or the school's AP participation rate and how well the students did on those tests. Tiebeakers were used to determine ranks of schools that achieved the same College Readiness Index.

    When was the last time you told someone they inspire you to go to work each morning?

    Teachers at Oak Park High School in Kansas City, Missouri, did just that this September, when they pulled individual students out of class to tell them just how much they appreciated them.

    The students' reactions, which were captured (捕捉) on video and shared on YouTube in a now-viral video, ranged from shy thanks to hugs and tears.

    “I have been challenged to find a student who makes me want to come to school every day,” says one teacher in the video, “and that's you.”

    Jamie McSparin, a teacher in charge of the school's academy program for at-risk sophomores （二年级学生）and juniors, posed the challenge, writes ABC News.

    “Initially when we pulled the kids out, they all thought they were in trouble,” McSparin told ABC News. “Any teacher-student interaction always seems to be negative (消极的), and that was something that bothered me, too. No matter if they're a good kid or a trouble maker or anything, they always thought they were in trouble,” she says.

    McSparin says she got the idea for the project after attending a professional development workshop this summer called the power of positivity.

    “I like the idea of letting students know they are appreciated, because we do appreciate them, I just don't think we say it enough,” she told local news outlet WDAF-TV.

    It's safe to say the challenge was effective.

    “I feel special,” said one of the boys in the video. “You should,” said his teacher. “You are special.”

    In one of the world's most forbidding environments, Polar bears spend !heir summers roaming (漫步) the Arctic on large pieces of floating ice. They drift(漂移) for hundreds of miles, finding mates, hunting for seals , and fatting themselves up for the winter. Without the floating ice , the world's largest bears could not survive Yet at this moment , the polar bears' Arctic habitat (栖息地) is melting away under it because of global warming.

    Over the past three decades, more than a million square miles of floating ice has disappeared Scientists predict that, if the current rate of global warming continues, most, if not all, of the bears' floating ice will be gone by 2100. As a result, the world's polar bears could face global dying out by the end of this century.

    Already, the ice on the southern edge of the polar bears' habitat is melting about three weeks earlier than in the past. The loss of those key weeks leaves the bears less time to hunt, eat and store up fat. Once the ice melts, the bears must fast for up to eight months on land until the floating ice returns. As a result of early melting, there has been a 14 percent decline in the Hudson Bay polar bear population over the past ten years- a fall clearly caused by global warming.

    Besides, a growing number of polar bears may be drowning (溺水) as they are forced to swim more often, and for longer distances, looking for ice sheets(冰原). According to a report by the US Mincrals Management Service, researchers observed four dead polar bears floating 60miles off Alaska in September of2006 and said it was likely that many other bears swimming far off shore also drowned. Scientists have concluded that the worldwide population of about 20,000polar bears is likely to become smaller by more than 30 percent in the next 35 to 50 years alone.

    As health care costs continue to rise, a growing number of companies are working out programs designed to keep their employees healthy.

    Thomas Chapple is the senior vice president. “It's really important to us because medical costs are going up like crazy, he says. This company spends more than 200 million a year on medical costs for its employees around the country. The best thing we have seen as a way to control the medical cost is individual fitness.”

    We have a fitness center, “Shawn Flaherty, director of public relations for Freddie Mac.,” says, “We have a health benefits plan that encourages people to work out three times a week, get cholesterol (胆固醇) checks, as well as 'not to smoke.' If they do that, it will cost them less for the health benefits.”

    Rachelle Clark works for Freddie Mac. “I feel great. You know the benefit is rewarding. I like to look good and feel healthy. I am just fortunate that I work for the company that provides some type of facility for the employees.”

    While on-site fitness centers are popular, some companies pay membership fees at local gyms for employees. The companies also offer classes such as boxing, yoga and dancing. Employees see those health programs as a valuable benefit.

    Tom Brook exercises five days a week. As a newspaper reporter he has a tight schedule, although Tom says it's not that difficult for him to make time for a workout. “It is great. It is right here where we work,” says Tom, “So everybody gets a chance to use it whenever they want to. I have lost weight and never been in better shape.”

    The programs may not be a magic cure for rising health costs, but they seem to have a positive impact on both employers and employees.

    Elephants are able to know the difference between a man and a woman, and can tell an adult (成年人) from a child—all from the sound of a human voice. This is according to a study in which researchers played voice recordings to wild African elephants.

    The animals showed more fear when they heard the voices of adult Masai men. Usually Masai people hunt elephants, and this suggests that animals have grown to listen for and avoid them.

    Prof. Karen McComb and Dr Graeme Shannon from the University of Sussex led the study. They explained that in former research they had used similar experiments to show that elephants could tell—from the sound of a lion—whether the animal was a female (雌性) or a more dangerous male (雄性).

    Prof  McComb wanted to find out if the animals used their very sharp sense of hearing to recognize danger from humans.

    The scientists recorded Masai men, women and children saying, in their own language, "Look, look over there, a group of elephants are coming." They also recorded Kamba men saying this phrase.

    Masai people often come across elephants, which can result in violent (暴力的) hunting. Kamba people, however, mainly feed on agriculture, which does not generally bring them into violent touch with the animals.

    When the team played recordings of these different voices through a hidden speaker, they found that elephant family groups showed more fear in response to the voice of a Masai man, than to a Kamba man's voice. And the adult male Masai voices caused far more violent response than the voices of women or boys.