Have you ever lost your direction? Then you might find satellite navigation(satnav) systems(卫星定位系统) helpful.

    A satnav system uses groups of satellites. They send information to a receiver(接收器), such as your smartphone. Then they can find where you are.

The earliest satnav system is the Global Positioning System(GPS) of the United States. The US has put 24 satellites into space to make sure GPS can locate(定位) a person correctly and globally. Likewise, Russia's GLONASS and European Union's Galileo can also work globally.

    But China is catching up, building its own BeiDou Navigation Satellite System. BeiDou is China's homegrown satnav system, reported Xinhua. It was set up in 2000, when China sent BeiDou's first navigation experiment satellite into space. With it, China became the third country to build a satnav system after the US and Russia.

    BeiDou can find you wherever you are. It helps you go faster by finding shortcuts(捷径) and using correct directions. When you are in trouble and call the police, they will know exactly where you are if you have a cellphone that uses BeiDou.

    Today, there are more than 20 BeiDou satellites above our heads. And the system is able to offer open services to the Asia-Pacific region(亚太地区).

    In November, China plans to send more BeiDou-3 satellites into space. BeiDou-3's position accuracy(准确度) is less than five meters, Ran Chengqi, a senior designer of the satellite navigation system, told China Daily.

    By 2020, BeiDou is planned to have 35 satellites and begin serving globally, reported Xinhua.

    Have you ever found yourself in this situation：You hear a song you used to sing when you were a child-a bit of nostalgia（怀旧）or "blast from the past，"as we say．But it is not a distant childhood memory．The words come back to you as clearly as when you sang them all those years ago．

    Researchers at the University of Edinburgh studied the relationship between music and remembering a foreign language．They found that remembering words in a song was the best way to remember even one of the most difficult languages．

    Here is what they did. Researchers took 60 adults and randomly divided them into three groups of 20．Then they gave the groups three different types of "listen-and-repeat" learning conditions．Researchers had one group simply speak the words．They had the second group speak the words to a rhythm，or beat．And they asked the third group to sing the words．

    All three groups studied words from the Hungarian language for 15minutes．Then they took part in a series of language tests to see what they remembered．

    Why Hungarian，you ask ? Researchers said they chose Hungarian because not many people know the language．It does not share any roots with Germanic or Romance languages，such as Italian or Spanish．After the tests were over，the singers came out on top．The people who learned these new Hungarian words by singing them showed a higher overall performance．They did the best in four out of five of the tests．They also performed two times better than those who simply learned the words by speaking them．

    Dr．Katie Overy says singing could lead to new ways to learn a foreign language．The brain likes to remember things when they are contained in a catchy 3，or memorable 4，tune 5．

    Dr．Ludke said the findings could help those who struggle to learn foreign languages．On the University of Edinburgh's website Dr．Ludke writes，"This study provides the first experimental evidence that a listen-and-repeat singing method can support foreign language learning，and opens the door for future research in this area．"

    Bees and other pollinators（传粉者）  use smells to track down fresh flowers. Air pollutants can weaken those scents（气味）.  Scientists had worried this might make it harder for some pollinators to find a meal.

    Many animals help pollinate plants. Species that do this include bees, butterflies, etc. But for many reasons, the pollinators available to help plants in this way are decreasing. Scientists think a loss of habitat（栖息地）can be one factor. Diseases and exposure to poisonous chemicals also count.

    Jose Fuentes points to air pollution as another possible factor. He's an atmospheric scientist at Pennsylvania State University. In an earlier study, he showed some air pollutants could weaken or destroy scents emitted(发出)by flowers.

    Searching for a meal leaves pollinators out in the open and at risk of becoming other animal's lunch. And any time spent hunting food is time away from their duties back home, like protecting a hive（蜂巢）or nest, explains T'ai Roulston. He's an insect biologist at Virginia University. Roulston worked with Fuentes on the new study.

    In the study, the researchers focused on five kinds of representative scent molecules(分子)plants emit. One molecule they looked at, for example, is called beta-myrcene. Many flowers give off this chemical into the air.  Normally, this gas can travel some 800 meters from its flower source. But in polluted air, this same molecule could travel only half as far.

    Worse still, air pollution might do more than just weaken scent plumes（气味烟云）．Chemical reactions between air pollutants and plumes may transform the flowers' smells, creating new scents. And these scents may be unrecognizable to pollinators.

    That's certainly Fuentes' concern.  So, he says his next research project will look at how insects handle any new flower scent. "It's possible that some insects will change ways to detect and use these new molecules to find food," he says.

    Are you an optimist? Do you look at your glass and see it as half full? Do you believe that every cloud has a silver lining and that generally things turn out for the best? Do you believe that if something is meant to be, it will be? If you reply "yes" to all of these questions, then you are an optimist. You probably are enthusiastic, cheerful and outgoing. You may well be successful at work and in love.

    But you may be misguided because things don't turn out for the best. You may believe that when one door closes another one opens (For example, you may fail to land a new job, but another chance will come around soon). Wrong. When one door closes, another door slams in your face. That's bitter reality.

    Now a book has been published which confirms what we pessimists(悲观者) have suspected all along. It's called The Positive Power of Defensive Pessimism. Its author argues that defensive pessimism can lead to positive results. Defensive pessimism is a strategy used to manage fear, anxiety and worry. Defensive pessimists prepare for things by setting low outcomes for themselves. They carefully consider everything that may go wrong and plan for ways to handle these problems. And this gives them a sense of control. Lawrence Sanno, a psychology professor, says, "What's interesting about defensive pessimists is that they tend to be very successful people, so their low opinion of the situation's outcomes is not realistic. They use it to motivate themselves to perform better."

    So far, so good. This is not rocket science. Defensive pessimists prepare carefully and consider what might go wrong, whether at work, on a date or even in a sports game. It makes sense to have a backup plan. There are many sayings in English urging caution. For example, "Don't put all your eggs in one basket", and "Don't count your chickens until they hatch." To have a confident and optimistic approach to life's problems is good. But listen to what Woody Alien, the American comedian says, "Confidence is what you have before you understand the problem."

    There are pros and cons to being an optimist and a pessimist. Don't feel bad if you see the glass half empty. You are a realist. But lighten up and hook up with someone who sees the same glass half full.

    We all have some people whom we respect very much, like our family members, our friends or our teachers.

    Respect often means different things to different people. There are several aspects that many people can agree on, though. For example, at its most basic level, respect means being kind and considerate to others.

    Respect can take many forms. Don't make fun of others. Put yourself in other people's shoes and think about how they feel. Remember the Golden Rule: treat others the same way you'd want to be treated.

    Respect is important because it sets the proper stage for all our human interactions. Friendship, love, and even basic communication must all start with respect.

    Everyone wants to be respected. To get respect, though, you must also show respect for others. It's always a two-way street. You can't be impolite to others and expect respect in return.

    It's easy to show respect. Be polite. Look for the best in people rather than concentrating on their mistakes. Show compassion to others and try to put their interests before your own. Make others comfortable when they're uneasy. Help out whenever you can. When you pay it forward, amazing things can happen.

    And be respectful to everyone. The world is an unbelievably huge place filled with billions of people, each one of whom is unique and special. And they all deserve your respect!

    Be careful, though. Not everyone will show you respect all the time. In fact, you'll probably see examples of impolite behaviour each and every day. How you respond to impolite behaviour, though, can make a huge difference.

    If you choose to respond to impolite behaviour by acting rudely yourself, you've gained nothing. You've only continued the pattern of impolite behaviour and set a bad example. Instead, act respectfully and set a good example. Consistently acting respectfully might just help others learn from your example!

October 15th is Global Handwashing Day. Activities are planned in more than twenty countries to get millions of people in the developing world to wash their hands with soap.

Experts say people around the world wash their hands but very few use soap at so-called extremely important moments. These include after using the toilet, after cleaning a baby and before touching food.

Global Handwashing Day is the idea of the Public Private Partnership for handwashing with soap. The goal, they say, is to create a culture of handwashing with soap. The organizers say all soaps are equally effective at removing disease-causing germs. They say the correct way to wash is to wet your hands with a small amount of water and cover them with soap. Rub it into all areas, including under the fingernails.  Then, wash well under running water. Finally, dry your hands with a clean cloth.

The Partnership says soap is important because it increases the time that people spend washing. Soap also helps to break up the dirt that holds most of the germs.  And it usually leaves a pleasant smell, which increases the chances that people will wash again.

It also says that washing hands with soap before eating and after using the toilet could save more lives than any medicine. It could help reduce cases of diarrhea, which is the second leading cause of child deaths, killing more than one and a half million children a year, by almost half.