This week is Computer Science Education Week. During the week, students around the world will be taking part in an "Hour of Code" and learning a little about programming computers. This year, there will be more than 200.000 events in over 180 countries.

    The U.S. Congress first created Computer Science Education Week in 2009 to remember Grace Hopper, one of the women who played an important part in the early days of computers.

    Hadi Partovi came up with the idea of the Hour of Code. He thinks coding is an important skill and that it's important for schools to teach computer science. He started the Hour of Code in 2013 because he was worried that computer science was not a big part of what schools taught in most states.

    To spread his idea, he got the help from many famous people. Some were famous for working with computers, like Bill Gates. Others were famous in other areas. Mr. Partovi got a lot of money for his idea from big companies like Facebook. Google, and Microsoft.

    Students who take part in the Hour of Code complete a short coding challenge that is broken down into small, simple steps. The challenge is supposed to take about an hour in all.

    To raise the interest of students, the challenges are often tied in with popular movies or games. For example, challenges have been built around Angry Birds. Mine Craft. Frozen. and Star Wars—One test of the program's success is whether students keep going once the time is up. It turns out that many of them do. Last year, teachers reported that 92% of their students coded for more than an hour.

    Do you think laughter can help you deal with pain? Scientists from Britain did two experiments(实验). The first was done in a lab. People wore special wristbands(腕带). Some of them were asked to watch comedies while others watched serious programs. Then the scientists tightened(勒紧)the wristbands to see how much pain the people could feel.

    The other test was done at an art festival. Some people watched a comedy show and others watched a drama(戏剧). At the same time, they had to put their backs against the wall and keep their legs bent(弯曲的)just like sitting on a chair. They did this before and after the show.

Scientists found that just 15 minutes of laughter improves people's ability to stand pain by 10%. However, the serious programs and the drama didn't make a difference to pain at all.

    The study found that the magic power of laughter comes from endorphins(内啡肽). These are chemicals(化学物质). They are produced by the human body. They make you feel less pain and can make people feel happier. Exercise can produce endorphins. Your muscles(肌肉)move in and out when you are laughing. Scientists believe that this makes your muscles tiring, so we start to produce endorphins.

    Scientists also found that the only real and relaxing laughter works not just polite laughter.

    Next time you have a headache, get together with a group of Mends, watch a funny movie and laugh. You will soon feel a lot better because laughter is the best medicine.

    It's important to learn about protecting our environment. Here is a 5R rule for us:

    Reduce

    If you want to reduce waste, you should use things wisely(明智地). A larger number of trees are cut down to make paper. If everyone uses paper carelessly, soon we will not have any trees left. Other things are also being wasted, and people don't know what to do with the waste in big cities. So it is necessary to use things wisely.

    Reuse

    You should always think of reusing the usable things before throwing them away. For example, you can give your clothes you do not wear any more to the poor. In a family, you may pass on such clothes to younger brothers or sisters.

    Recycle

    Bottles, cans and paper can easily be recycled. By recycling them we save lots of time and money. For example, Coke cans are sent to a factory, where they are smashed flat (压平) and melted(融化) and the metal things are made for new Coke cans.

    Recover(恢复)

    When you buy a box of apples, there may be a few rotten(腐烂的) apples, you have two choices(选择): One is to throw the whole apples away, or you can cut off the rotten parts and keep the good parts. In the way, you are recovering the eatable(能吃的) parts of food.

    Repair

    If one of the legs of your table is broken, you can repair it. If you want to change for better ones, it is better for you to sell the old things or give them to other people who can use them after doing some repair.