In London's art gallery six or seven men, mostly in their 30s, are busy painting the walls with new designs in colorful lettering and clever tricks. Tins of spray paint and beer stand on the ground. The atmosphere is not unlike that of a golf course: a mix of concentration and relaxation.

    Graffiti(涂鸦) painting is traditionally a daring hobby. Teenagers avoid security guards to put their names on trains and buses. But over the past decade that has almost disappeared from Britain's cities. Between 2007 and 2017 the number of incidents of graffiti recorded by the British Transport Police fell by 63%. A survey by the environment ministry shows that fewer places are damaged by tags(绘名) than ever. Graffiti are increasingly limited to only a few walls. In time the practice may die out entirely.

    The most obvious reason for the decline in tagging and train-painting is better policing, says Keegan Webb, who runs The London Vandal, a graffiti blog (博客). Numerous cameras mean it is harder to get away with painting illegally. And punishments are more severe. A generational change is apparent, too. Now teenagers prefer to play with iPads and video games. Those who do get involved tend to prefer street art to graffiti. And the internet helps painters win far more attention by posting pictures online than they can by breaking into a railway yard.

    Taggers and graffiti artists mostly grew up in the 1980s and 1990s. Those men are now older and less willing to take risks. "We can't run away from the police any more," says Ben Eine, who turned from tagging to street art. The hip-hop culture that inspired graffiti in the first place has faded. Video games and comic books provide more inspiration than music.

    Graffiti may eventually disappear. But for now the hobby is almost respectable. Mr Eine says he has lots of friends who used to paint trains. Now with wives and children, they paint abandoned houses at the weekend. It has become something to do on a Sunday afternoon—a slightly healthier alternative to sitting watching the football.

    What is a big dream? {#blank#}1{#/blank#} Or, is a big dream something that provides only entertainment? Children dream big dreams, but there are three barriers to realizing dreams. They often kill them before they ever have a chance to grow.

The Self

    Immediately following the birth of a big dream, a negative self-talk takes over and gives all the reasons why it cannot happen. This inside voice is the ego (自我). It's there for protecting and should be listened to. {#blank#}2{#/blank#} Most people are influenced by the inside voice. That's why only a handful of people make their dream come true.

{#blank#}3{#/blank#}

    Family and friends are a lot like the ego. They want to protect those they love, so they will often list all the reasons why the big dreams won't come true. Sometimes, family and friends destroy dreams of those they love most, out of their own fear of being left behind.

The World

    If one gets past the first two barriers, one has to face the world.{#blank#}4{#/blank#} In the past, big dreamers were locked up and sometimes even killed when they were shown to the world. Fortunately, in most of the world today, big dreamers just get laughed at.

    The way to realize a big dream is with confidence and action. When children have confidence and then take action, they will be ready to accept any failure. The truth is that every great dreamer whose dreams have never seen the light of success knows failure well.{#blank#}5{#/blank#}

A. Family and Friends.

B. How big Dreams Die.

C. Does a big dream show one's future?

D. They simply fail until they succeed.

E. it is the last and the most terrible barrier.

F. Sometimes it is right, but more often it is wrong.

G. And their big dream is to be a rock star or a famous artist.

    Below is a selection from a popular science book.

    If blood is red, why are veins（静脉） blue?

    Actually, veins are not blue at all. They are more of a clear, yellowish color. Although blood looks red when it's outside the body, when it's sitting in the vein near the surface of the skin, it's more of a dark reddish purple color. At the right depth, these blood-filled veins reflect less red light than the surrounding skin, making them look blue by comparison.

    Which works harder, you heart or your brain?

    That kind of depends on whether you're busy thinking or busy exercising. Your heart works up to three times harder during exercise, and shifts enough blood over a lifetime to fill a supertanker. But in the long run, your brain probably tips it, because even when you're sitting still your brain is using twice as much energy as your heart, and it takes four to five times as much blood to feed it.

    Why do teeth fall out, and why don't they grow back in grown-ups?

    Baby (or “milk”) teeth do not last long; they fall out to make bigger room for bigger, stronger adult teeth later on. Adult teeth fall our when they become damaged, decayed and infected by bacteria. Once this second set of teeth has grown in, you're done. When they're gone, they are gone. This is because nature figures you're set for life, and what controls regrowth of your teeth switches off.

    Do old people shrink as they age?

Yes and no. Many people do get shorter as they age. But, when they do, it isn't because they're shrinking all over. They lose height as their spine（脊柱） becomes shorter and more curved due to disuse and the effect of gravity(重力). Many (but not all) men and women do lose height as they get older. Men lose and average of 3-4 cm in height as they age, while women may lose 5 cm or more. If you live to be 200 years old, would you keep shrinking till you were, like 60 cm tall, like a little boy again? No, because old people don't really shrink! It is not that they are growing backwards —- their legs, arms and backbones getting shorter. When they do get shorter, it's because the spine has shortened a little. Or, more often, become more bent and curved.

    Why does spinning make you dizzy（眩晕的）?

    Because your brain gets confused between what you're seeing and what you're feeling. The brain senses that you're spinning using special gravity-and-motion-sensing organs in your inner ear, which work together with your eyes to keep your vision balance stable. But when you suddenly stop spinning the system goes out of control, and your brain thinks you'removing while you're not.

    Where do feelings and emotions come from?

Mostly from an ancient part of the brain called the limbic system. All mammals have this brain area —- from mice to dogs, cats, and humans. So all mammals feel basic emotions like fear, pain and pleasure. But since human feelings also involve other, newer bits of the brain, we feel more complex emotions than any other animal on this planet.

    If exercise wears you out, how can it be good for you?

    Because our bodies adapt to everything we do to them. And as far as your body is concerned, it's “use it, or lose it”! It's not that exercise makes you healthy, it's more that a lack of exercise leaves your body weak and easily affected by disease

    My teacher held up a piece of broken glass and asked, "Who broke this window?"

    Thirty boys tried to think about not only what they had done, but also what our teacher may have found out. She seldom became angry, but she was this time.

    "Oh," I thought. I was the one who broke the window. It was caused by a naughty throw of a baseball. If I admitted guilt, I would be in a lot of trouble. How would I be able to pay for a big window like that? I didn't even get an allowance. "My father is going to have a fit." I thought. I didn't want to raise my hand, but some force much stronger than I was pulled it skyward. I told the truth. "I did it." It was hard enough to say what I had.

    My teacher took down a book from one of our library shelves and I had never known my teacher to strike a student, but I feared she was going to start with me.

    "I know how you like bird," she said as she stood looking down at my guilt-ridden face. "Here is that field guide about birds that you are constantly checking out. It is yours now. It's time we got a new one for the school anyway. You will not be punished as long as you remember that I am not rewarding you for your misdeed, I am rewarding you for your truthfulness."

I couldn't believe it! I wasn't being punished and I was getting my own bird field guide—the very one that I had been saving up money to buy.

    All that remains of that day is my memory and the lesson my teacher taught me. That lesson stays with me every day, and it will echo forever.

Top Music Festivals in 2021

Coachella

Selling out fast every year, the Indio desert becomes a fashionable place where the coolest bands are watched by trendy people and celebrities. Near the top of everyone's bucket list of festivals, Coachella is a constant source of annual expectation and a hotbed for musical discussion.

When &. where: April 9-11 &. 16-18, 2021; Indio

Ultra Music Festival

Seen as the ultimate gathering for electronic music fans across the nation and globe, the streets of Miami turn into a bold and bumping party with popular DJs playing what will be the sounds of summer.

When & where: March 26-28, 2021; Miami

South By South West

Regarded as the ultimate trend-setter and launcher of careers, SXSW is an annual showcase of music, films and interactive highlights enjoyed through performances, showcases, talks, screenings and more. Virtually taking over the city of Austin, everyone in the world of music from fans to media flock here to discover the next big thing.

When &, where: March 16-20, 2021; Austin

The Governors Ball Music Festival

Another event which proves the music loving potential of Randall's Island Park is Governors Ball, an exciting and infectious mix of rock, hip-hop, electronic, pop and folk. Providing a variety of music and food tastes, whether you look to kick back and relax or dance to the beats, Governors Ball has what you want.

When & where: June 11-14, 2021; New York