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.

    A small group of people around the world have started implanting(移植) microchips to link the body and the computer.

    Mr. Donelson and three friends, who had driven 100 miles from their homes in Loockport, New York, to have the implants put in by Dr. Jesse Villemaire, whom they had persuaded to do the work, are part of a small group, about 30 people around the world, who have independently put in microchips into their bodies, according to Web-based reports.

    At a shop William Donelson was having a four-millimeter-wide needle put into his left hand. “I'm set,”he said with a deep breath. He watched as the needle pierced(刺穿) the fleshy webbing between his thumb and a microchip was set under his skin. At last he would be able to do what he had long imagined: strengthen his body's powers through technology.

    By putting the chip inside—a radio frequency identification device (RFID)—Mr. Donelson would have at his fingertips the same magic that makes safety gates open with a knock of a card, and bridge and tunnel traffic flow smoothly with an E-Zpass. With a wave of his hand he plans to connect with his computer, open doors and unlock his car.

    Implanting the chip was relatively simple task but very meaningful to Mr. Doneselson, a 21-year-old computer networking student so interested in the link between technology and the body that he has data-input jacks(数据输入插空) inside his body. They might lead to an imagined future when people can be connected directly into computers. His new chip is enclosed in a glass container no bigger than a piece of rice and has a small memory where he has stored the words “Technology”.

    Some doctors have done the piercing in people's homes, and others have implanted chips in their offices after patients signed forms showing the fact that long-term studies have not been done on their safety. Piercers treat the implants much like any other medical operation steps, instructing people to keep the site dry, and advising them that swelling and redness should last a week.

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    Writing it down

    Unlike some other European languages, English is a little tricky when it comes to writing. How a word is pronounced and how it is actually spelt can be very different things.

    Same spelling, different meanings

Imagine, then, a situation where two words are spelt and pronounced exactly the same way, but have completely different meanings. Welcome to the world of homonyms（同形同音异义词）. Take, for example, the word "fair"—it can be a kind of festival, an adjective to describe the colour of your hair or how you should play a game. Or "leg", which can be attached to a person, or a table and can also be a distance you travel, or a part of a competition.

Don't take it literally（字面意思）

So how do you know which meaning someone is referring to? You don't, except by the context. Obviously, if someone asks you to "give them a hand", they don't want you to remove what is at the end of your arm.

What's in a name?

    Sometimes even the context doesn't help much—the result can be amusing. These sentences play with the double meaning of a noun:

    Sentence 1: I used to be a banker, but I lost interest.

Sentence 2: A small boy swallowed some coins and had to go to hospital. When his grandmother phoned to ask how he was, the nurse said: "No change yet".

    More ambiguity（歧义）

    Sentence 3 plays with the different meanings of a verb:

    Sentence 3: I wondered why the ball was getting bigger. Then it hit me.

Double trouble

    And sometimes a word can be a noun and a verb, but have different meanings. Can you work this one out?

    Sentence 4: Time flies like an arrow. Fruit flies like a banana.

    If you like these homonyms, you will be pleased to know that English has plenty more!

B

Find Your Adventure at the Space and Aviation(航空) Center

    If you're looking for a unique adventure, the Space and Aviation Center (SAC) is the place to be. The Center offers programs designed to challenge and inspire with hands-on tasks and lots of fun.

    More than 750,000 have graduated from SAC, with many seeking employment in engineering, aviation, education, medicine and a wide variety of other professions. They come to camp, wanting to know what it is like to be an astronaut or a pilot, and they leave with real-world applications for what they're studying in the classroom.

    For the trainees, the programs also offer a great way to earn merit badges(荣誉徽章). At Space Camp, trainees can earn their Space Exploration badge as they build and fire model rockets, learn about space tasks and try simulated(模拟) flying to space with the crew from all over the world. The Aviation Challenge program gives trainees the chance to earn their Aviation badge. They learn the principles of flight and test their operating skills in the cockpit(驾驶舱) of a variety of flight simulators. Trainees also get a good start on their Wilderness Survival badge as they learn about water- and land-survival through designed tasks and their search and rescue of ＂downed＂ pilot.

    With all the programs, teamwork is key as trainees learn the importance of leadership and being part of a bigger task.

    All this fun is available for ages 9 to 18. Families can enjoy the experience together, too, with Family Camp programs for families with children as young as 7.

    Stay an hour or stay a week — there is something here for everyone!

    For more details, please visit us online at www.oursac.com.

    Good afternoon, and welcome to England. We hope that your visit here will be a pleasant one. Today, I'd like to draw your attention to a few of our laws.

    The first one is about drinking. Now, you may not buy wine in this country if you are under 18 years old, nor may your friends buy it for you.

    Secondly, noise. Enjoy yourselves, but please don't make unnecessary noise. We ask you to respect other people who may wish to be quiet.

    Thirdly, crossing the road. Be careful. The traffic moves on the left side of the road in this country. Use pedestrian crossings（人行道） and don't take any chances（冒险） when crossing the road.

    My next point is about rubbish. It isn't a law to drop rubbish in the street. When you have something to throw away, please put it in your pocket and take it home, or put it in a dustbin.

    Finally, about smoking. It is against the law to buy cigarettes if you are under 16.

    If you request any help, you should contact the police, who will be glad to help you. You can call, write, or directly go to ask any policeman.

    Two of the saddest words in the English language are "if only". I live my life with the goal of never having to say those words, because they convey regret, lost opportunities, mistakes, and disappointment.

    My father is famous in our family for saying "Take the extra minute to do it right." I always try to live by the "extra minute" rule. When my children were young and likely to cause accidents, I always thought about what I could do to avoid an "if only" moment, whether it was something minor like moving a cup full of hot coffee away from the edge of a counter, or something that required a little more work such as taping padding (衬垫) onto the sharp corners of a glass coffee table.

    I don't only avoid those "if only" moments when it comes to safety. It's equally important to avoid "if only" in our personal relationships. We all know people who lost a loved one and regretted that they had foregone an opportunity to say "I love you" or "I forgive you." When my father announced he was going to the eye doctor across from my office on Good Friday, I told him that it was a holiday for my company and I wouldn't be here. But then I thought about the fact that he was 84 years old and I realized that I shouldn't give up an opportunity to see him. I called him and told him I had decided to go to work on my day off after all.

    I know there will still be occasions when I have to say "if only" about something, but my life is definitely better because of my policy of doing everything possible to avoid that eventuality. And even though it takes an extra minute to do something right, or it occasionally takes an hour or two in my busy schedule to make a personal connection, I know that I'm doing the right thing. I'm buying myself peace of mind and that's the best kind of insurance for my emotional well-being.