Flu easily spreads from one person to another. This is especially true to people who are weak. If you are weak, you are more likely to catch flu easily. Do you know how you can avoid flu?

    Keep in good health

    The best antidote (解药) to illness is good health. You can eat everything you want but make sure that your diet is healthy. The healthier you are, the better for you to avoid any type of illness around. Most doctors suggest plenty of fresh fruit juice and water in order that one can avoid flu.

    Stay away from people with flu

    If a member of the family or a friend has flu, stay away from them until they are well. Flu is very communicable and you can catch it by going with the person with flu. Wear a mask (面罩) and avoid using things that the person with flu is using.

    Exercise

    Exercising will make you stronger which means a stronger immune (免疫的) system too. Exercise often so that your body will keep healthy. It doesn't matter what kind of exercise.

    What is important is you are making your body stronger to prevent illness from attacking you.

    Be happy

    Happy people are healthy people. Their life is stress-free, so they are more likely to be safe from illness. If you are unhappy, which affects your immune system, you will easily get sick.

    Avoiding the flu is easy. Just boost (增强) your immune system and it will take care of the rest.

    Are children becoming addicted to the Internet?

    Children are becoming addicted to the Internet and for many it is one drug that can't be beaten. Not all children, but an alarming number of them are being swept up in this age of digital information.

    Websites like Myspace, Youtube, and Facebook, are becoming so popular that many kids can't help but to be addicted to them just in order to fit. Why not become part of a society where you judged by how many friends on a friend list ? What has become of the world , when instead of calling your best friend on the phone you send them a message electronically and wait around for hours to see if they get on and read it ?Often on the web there just aren't enough adults setting kids straight and too many teenagers causing trouble .

    However, it is biased to claim all kids are addicted, or even that all kids who are addicted to the web are negatively affected by it. While the web can be a large waste pool of negative influence, it is also a wealth of positive knowledge, friendly social networking, and even gateways to future employment. Perhaps it isn't so important whether or not a child is addicted to the web and more important that parents know exactly what the kids are doing there.

    Many computers have optional parent controls that allow parents to block the children from entering certain types of sites, or even individual ones. Such programs are unfortunately not used enough by today's parents, who in many cases are caught up on computers themselves. All one needs to do is google search parental controls and you will be provided with any number of companies that can help with programs for tracing child activity and, if necessary, limit time spent on the Internet .

    A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components,” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing the components together. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, and then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    In recent years, much of the sea ice that polar bears use as a hunting platform for seal meals has melted, forcing some bears — particularly young males — farther north or onto land, where they are not as skilled at hunting. When stuck on land for months, a polar bear typically is forced to survive on its own fat reserves.

    The bears were listed earlier this year as a threatened species under the U. S. Endangered Species Act as populations have declined. Meanwhile, snow geese are booming near the western Hudson Bay, and there are in fact too many of them. Their eggs can be a good food source. The geese nest on tundra (冻原；苔原) that some bears have retreated to.

    "Over 40 years, six subadult (接近成年的) male bears were seen among snow goose nests, and four of them were sighted after the year 2000," says Robert Rockwell. "I've seen a subadult male eat goose eggs whole or press its nose against the shell, break it, and eat the contents."

    Ice is melting, on average, 0.72 days earlier each year in the region studied. Snow geese are hatching eggs about 0.16 days sooner each year, according to Rockwell and his graduate student Linda Gormezano. Current trends indicate that the arrival of polar bears will correspond to the average hatching period in 3.6 years, and egg consumption could become a viable option, which the researcher concluded in a statement released today.

    A polar bear, the largest land carnivore (食肉动物), would need to consume the eggs of 43 nests to replace the energy gained from the average day of hunting seals, but Rockwell and his colleagues figure that while many polar bears may starve in coming years, the resourceful animals just might survive disappearance.

    Polar bears survived a warm period about 125,000 years ago, when sea level was 12 to 18 feet higher than it is now and trees lived above the Arctic Circle, the scientists point out.  "They've been through the warm period before，" Rockwell said.

    The polar bears' potential movement to a diet of more eggs brought to mind a quote by Ilkoo Angutikjuak, an Inuit who lives in the Canadian province of Nunavut, in the February 2008 issue of Natural History magazine, Rockwell said. Angutikjuak said: "The animals will adapt. I've heard that because they depend on sea ice, polar bears will disappear, but I don't believe it. They are very adaptable. As the sea ice changes, polar bears might get skinnier and some might die, but I don't think they will disappear."

    American families are accustomed to settling in faraway places, which has been a national phenomenon. Decades of data, including a more recent Gallup study, characterizes the US as one of the most geographically mobile countries in the world. "About one in four US adults(24 percent) has reported moving within the country in the past five years." the reported noted. With the exception of Finns(23 percent) and Norwegians(22 percent), Americans move considerably more than their European peers.

    Though some may move for love or family, the major reason why Americans choose to move around is, unsurprisingly, related to work. Citing data from the Current Population Survey, a post on the blog of the New York Fed noted that between 1998 and 2013, "slightly more than half of interstate(州际的) migrants said they moved for employment­related reasons—a category that includes moves undertaken for new jobs, job transfers, and easier commutes(通勤)."

    The seeking of opportunity, particularly for an immigrant nation, is a national mythology(神话) as well as an emotional attachment to work. A new working paper analyzed by Ben Steverman at Bloomberg suggests that workers in the US now" put in almost 25 percent more hours than Europeans" in a given year. This figure has steadily risen since the 1970s, when the hours logged by workers in Western Europe and the US were roughly the same.

    There are, of course, some internal factors. The US is much vaster than most European countries, plus it boasts(拥有) a common language. It is considered to be a sign of an efficient labor market that US workers can be persuaded to move to regions where there is a steady growth in jobs, such as the Sun Belt in recent years. And while American workers often have fewer labor protections than their European counterparts, as a report by the World Bank noted in 2012, American "labor laws give employers the power to fire, hire, or relocate(重新安置) workers according to their needs", a flexibility that is thought to aid economic growth. The World Band report added that the occupation of the average US employee in 2006 was 4 years, compared to 10 years in the European Union.

    Nevertheless, while Americans remain excessively mobile, FaithKarahan and Darious Li at the New York Fed are the latest to note that US workers are moving around less than before. During the 1980s, 3 percent of working­age Americans relocated to a different state each year; that figure had been cut in half by 2010." While part of the decline can be attributed to the Great Recession," the authors suggest," thisphenomenon took place over the course of several decades and is not necessarily related to the economic conditions."

    So what accounts for this phenomenon? A round­up of theories by Brad Plumer at The Washington Post included the aging of the US workforce, the further rise of two­income households, the burdens of real estate, evolving workplace culture, as well as the flat line of wages, which makes moving away for a job, on average, a less rewarding financial proposition.

    Karahan and Li put much stock in the effects of an aging workforce, to which they attribute at least half of the decline in interstate migration. "In short, a young individual today is moving less than a young person did in the 1980s because of the higher presence of older workers," they write, suggesting that employers have shifted their employment tactics(策略) to adapt to the changing demographics(人口统计数据) of the workforce. Needless to say, movies about this era in American life, in which fewer people set out to start lives in wide­ranging places, will probably be much less exciting.

    If you could have a superpower, what would it be? Other than flying and communicating with someone from his mind (which, let's be honest, would probably actually be awful), breathing underwater is one of the favorites. You can hang out with Aquaman and Ursula, and when the end of the world comes and we're all living under water, you'll be fine.

    With this in mind, a student at the Royal College of Art, London has designed a 3D-printed amphibious garment called AMPHIBIO —essentially a set of gills (鳃) —for this very purpose. According to Jun Kamei, a biomimicry designer and materials scientist, it is "for a future where humankind lives in the water".

    With the world set for a global temperature increase of 3. 2℃ (5. 7℉) by 2100, rising sea levels are a very real threat to large coastal cities, potentially affecting up to 2 billion people —or 26 percent of the current global population.

    Kamei's little device uses a specially designed porous (多孔的) material that fills oxygen again in the water and releases carbon dioxide. It is inspired by water-diving insects that create their own little scuba diving set by creating a protective bubble of air around their body thanks to their water repellent (防水的) skin.

    The technology is easily 3D-printable too, which will be great when we need them together. These "gills" could replace heavy and clumsy scuba equipment, making it more similar to free diving but for longer. This could have immediate applications for underwater rescue plans —the 12 boys rescued by divers from a flooded cave in Thailand, for example, where it took weeks to work out how to get the boys and the vital breathing equipment through those narrow tunnels.

    So far, the tech has only been tested as a working prototype, not actually on humans, so the dream may have to be on hold for now. And scaling up and testing on humans is Kamei's next plan. This may sound unbelievable, but Kamei insists he has a much more optimistic vision of the future.