We all know what a brain is. A doctor will tell you that the brain is the organ of the body in the head. It controls our body's functions, movements, emotions and thoughts. But a brain can mean so much more.

    A brain can also simply be a smart person. If a person is called brainy, he is smart and intelligent. If a family has many children but one of them is super smart, you could say, “He's the brains in the family.” And if you are the brains behind something, you are responsible for developing or organizing something. For example, Bill Gates is the brains behind Microsoft.

    Brain trust is a group of experts who give advice. Word experts say the phrase “brain trust” became popular when Franklin D. Roosevelt first ran for president in 1932. Several professors gave him advice on social and political issues（问题）facing the U.S. These professors were called his “brain trust”.

    These ways we use the word “brain” all make sense. But other ways we use the word are not so easy to understand. For example, to understand the next brain expression, you first need to know the word “drain”. As a verb, to drain means to remove something by letting it flew away. So a brain drain may sound like a disease where the brain flows out the ears. But, brain drain is when a country's most educated people leave their countries to live in another. The brains are, sort of, draining out of the country.

    However, if people are responsible for a great idea, you could say they brainstormed it. Here, brainstorm is not an act of weather. It is a process of thinking creatively about a complex topic. For example, business leaders may use brainstorming to create new products, and government leaders may brainstorm to solve problems.

    If people are brainwashed, it does not mean their brains are nice and clean. To brainwash means to make some accept new beliefs by using repeated pressure in a forceful or tricky way. Keep in mind that brainwash is never used in a positive way.

    Many people believe that you lose the ability to learn new languages as you get older. Language experts, however, will tell you that you're never too old to learn a new language. As you get older, it can be more difficult to learn a new language, though.

    Children and adults learn new languages in different ways. For children, language is their life. They study for thousands of hours every year, because they need to learn languages to become part of their communities. Adults, on the other hand, are already part of a language community. Learning a new language means becoming part of another language community, and adults rarely get the chance to practice as much as young children do.

    Moreover, children learning a new language are expected to make mistakes. This gives them freedom when learning to be daring and confident. Adults, however, often feel pressured to be perfect when learning a new language. This can discourage many people and make it even harder to learn a new language.

    When young children learn a new language, they come to see various languages as a “normal” part of society. This mindset(思维模式) helps them embrace learning a new language without feeling like they're doing something unusual or “too hard”.

    So if you want to learn a new language, go for it! It's never too late to learn a new language. If you're older, it may take more work, but it can be done. If you're a young child, though, now is the time to step out and learn a new language!

    We can make mistakes at any age. Some mistakes we make are about money. But most mistakes are about people. Did Jerry really care when I broke up with Helen? When I got that great job, did Jim really feel good about it, as a friend? Or did he envy my luck? And Paul-why didn't pick up that he was friendly just because I had a car? When we look back, doubts like these can make us feel bad. But when we look back, it's too late.

    Why do we go wrong about our friends or our enemies? Sometimes what people say hides their real meaning. And if we don't really listen we miss the feeling behind the words. Suppose someone tells you. You're a lucky dog. That's being friendly. But lucky dog? There's a bit of envy in those words. Maybe he doesn't see it himself. But bringing in the dog bit puts you down a little. What he may be saying is that doesn't think you deserve your luck.

    Just think of all the things you have to be thankful for another noise that says one thing and means another. It could mean that the speaker is trying to get you to see your problem as part of your life as a whole. But is he? Wrapped up in this phrase is the thought that your problem isn't important. It's telling you to think of all the starving people in the world when you haven't got a date for Saturday night.

    How can you tell the real meaning behind someone's words? One way is to take a good look at the person talking. Do his words fit the way he looks? Does what he says agree with the tone of voice? His posture（姿态）? The look in his eyes? Stop and think. The minute you spend thinking about the real meaning of what people to you may save another mistake.

    Race walking shares many fitness benefits with running, research shows, while most likely contributing to fewer injuries. It does, however, have its own problem.

    Race walkers are conditioned athletes. The longest track and field event at the Summer Olympics is the 50-kilometer race walk, which is about five miles longer than the marathon. But the sport's rules require that a race walker's knees stay straight through most of the leg swing and one foot remain in contact (接触) with the ground at all times. It's this strange form that makes race walking such an attractive activity, however, says Jaclyn Norberg, an assistant professor of exercise science at Salem State University in Salem, Mass.

    Like running, race walking is physically demanding, she says, According to most calculations, race walkers moving at a pace of six miles per hour would burn about 800 calories(卡路里) per hour, which is approximately twice as many as they would burn walking, although fewer than running, which would probably burn about 1,000 or more calories per hour.

    However, race walking does not pound the body as much as running does, Dr. Norberg says. According to her research, runners hit the ground with as much as four times their body weight per step, while race walkers, who do not leave the ground, create only about 1.4 times their body weight with each step.

    As a result, she says, some of the injuries associated with running, such as runner's knee, are uncommon among race walkers. But the sport's strange form does place considerable stress on the ankles and hips, so people with a history of such injuries might want to be cautious in adopting the sport. In fact, anyone wishing to try race walking should probably first consult a coach or experienced racer to learn proper technique, she says. It takes some practice.

I had never picked up a camera before my freshman year in 2012, when my journey to an artist began. For four years, I 1 G-Star School of The Arts, where my 2 for photography and filmmaking were awaken.

Having seen my first short film, my teacher came over, saying: "You got a good 3 . Why not consider doing this as your profession. I think you've got a 4 in it". Then, it clicked. I, therefore, 5 my bank account and bought my first camera.

Since then, I was amazed by the 6 the world has to offer. I have to 7 , though: I, shy and chicken-hearted, tended to capture nature-related scenes, 8 anything to do with people.

As I was 9 my way, I started photographing myself, the only one I felt 10 with. The camera soon became my strongest 11 , serving as the tool for how I expressed myself. Gradually, I gained enough 12 to start taking photos of other people, greatly touched by how I was able to 13 the best in them through the lens (镜头).

Each year, I would look back on all of the shots I did that year and would 14 them to the first one I ever took in my career. Although the progress seemed substantial, I realized the key to growth as an artist is to never be 15 . This allows me to create progressively better work year after year.

One day as I drove toward my home in a small town, I passed the local bus station. Several passengers had already 1 a bus and were making their way to parked cars or setting off on foot to their various destinations.

I 2 as a group of people crossed the road in front of me. As I watched, I noticed an old lady struggling with a too large suitcase.Witnessing this lady and remembering similar 3 I had experienced in the past when traveling, I called out through the open passenger window, "Excuse me. Would you like a 4 ?" She stopped without answering. I said. "If you want to tell me where you are going, I'll drop you off. That suitcase looks 5 heavy." "Well, all right," she answered. When we got to her 6 , I helped her down with the suitcase. Suddenly, she said, "God bless you, lady. No one has ever given me a(n) 7 like that before. I hope someone will do a good turn for you one day." 

Shortly after 8 the suitcase lady, I decided to spend a day in the mountains. After driving my truck for nearly two hours, I found it had 9 something in the heavy bush, breaking down. Then in the 10 came the roar of motorbikes. I could see a string of bikes coming in my direction. As they drew nearer, I heard a(n) 11 voice say,"Do you need help, ma'am?". I almost sighed with 12 . The bikers formed a group around the truck. A couple of them got underneath it to check.

The whole adventure ended with my truck and me being 13 back to safety. I shall never forget the kindness of the motorcycle riders who 14 . Some people will say it was all just a happy 15 , but personally I like to believe the old proverb, "What goes around, comes around."