Augusto Esquivel is a sculptor who, in his own words, is “crazy with comparisons of reality and potential and the balance between them.” Perhaps the best example of what he's talking about are his most famous creations: the suspended(悬挂的) button sculptures.

    Made entirely from buttons hanging on various lengths of string, Esquivel's sculptures are made to look like common objects: a piano, a gumball machine, and even a toilet. If it wasn't for the clear string hanging above, these objects, these sculptures, would look solid, yet you can put your hands right through them. The process starts with him deciding on a subject and setting the acrylic （丙烯酸树脂）from where the buttons are being suspended. He buys buttons of different shapes and sizes, paints them with spray paint, and carefully hangs them. After that, it's a manner of hanging each individual button, which takes a lot of time. For his piano, for example, he individually hung over 60 pounds worth of tiny buttons.

    Esquivel's sculptures, while mostly housed inside art galleries, perfectly capture one of the main principles of street art: something that is eye-catching and something that invites interaction. Often the best sculptures outside the art galleries aren't the ones behind guards and fencing, but the ones people can go right up to and touch. In Vancouver, a series of laughing old men are attracting people for pictures and to just generally hang around, but the people who simply walk by and see the sculptures almost always leave with a smile on their face. That's good street art: it draws the viewer in rather than relying on a gallery to draw in an audience and point them to certain pieces.

    Esquivel's art is not only a presentation of talent, something that mentions larger philosophical questions, like the ones he stated above, but also just the right combination of interesting idea and painstaking work. One can look at his work in a critical way, or simply appreciate his idea and execution(艺术品的制作).

    Last week, we talked about the conflict(冲突) between sleepy teenagers and early morning classes. Many people commented(评论) on our website.

For example, Damla Ece in Turkey wrote: I agree with the idea of starting lessons later so teenagers can feel better in the morning. But sleeping more than seven hours can be wasting time for students.

    Tran in Vietnam disagreed: I think teenagers, on average, need eight to ten hours of sleep every day. It's useless to try to force them to concentrate while they can't concentrate.

    Afshin Heydari from Iran wrote: schools should start early to avoid heavy traffic later in the morning.

    And Suze from Jordan wrote: When I was a teenager, I enjoyed taking my courses as early as possible. That way I could find a long time in the day to do my own activities.

    But Azra from Kyrgyzstan said: the reason why schools start early here is a lack of classrooms.

    And Joruji in Japan wrote: When I was a teenager, I used to get up before six to go to school, which was far from home, and I don't remember having problems. I think nowadays the Internet, TV games and cell phones make teens go to sleep later.

    Thirty-year-old Kika in Spain said: In my opinion, young people are very lazy.

    But Dennis Jin disagreed: For high school students in China, we must reach the classroom at 6:20 in the morning and be back home usually at 10:00 in the evening. Then we'll have some extra schoolwork to do. Can you imagine how long we could sleep every day?

    Teenagers are not the only ones who suffer. Kathy in Canada wrote: My daughter likes complaining about everything in the morning, and I know that this is from lack of sleep. I wish schools should change their start time to 8:30 or 9:00 in the morning.

    And Naima Star in Libya wrote: Getting up so early in the morning and leaving the warm bed is so difficult, especially in the cold weather. It reminds me of that old song: "It's nice to get up in the morning, but it's nicer to stay in bed."

阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。

    Green is an important color in nature. It is the color of grass and the leaves on trees. It is also the color of most growing plants.

    Sometimes, the word “green” means young, fresh and growing. For example, a greenhorn is someone who has no experience. In the 15th century, a greenhorn was a young cow or an ox whose horns(角)had not yet developed. A century later, a greenhorn was a soldier who had no experience in war. By the 18th century, a greenhorn had the meaning it has today—a person who is new in a job.

    Someone who is good at growing plants is said to have a green thumb(大拇指). The expression comes from the early 20th century. A person with a green thumb can make plants grow quickly and well.

    Green is also the color used to describe the powerful feeling , jealousy(嫉妒). The green-eyed monster （怪物）is not a dangerous animal from outer space. It is an expression used about 400 years ago by the British writer William Shakespeare in his play “Othello”. It describes the unpleasant feeling when someone has something he wants. For example, a young man may suffer from the green-eyed monster if you get a pay rise and he does not.

    In most places in the world, a green light means to move ahead. In everyday speech, a green light means agree to continue with a project.

    Mr. and Mrs. Gordon were sitting on the sand, reading their magazines. Mr. Gordon was too stingy (吝啬的) to rent (租) a chair. Their twelve-year-old daughter, Sandra, was playing at the water's edge. Suddenly a huge wave lifted Sandra up and carried her out to sea. Fortunately, a lifeguard (救生员) was on duty and he saw the wave carry Sandra away. He ran along the beach and dived into the sea. He swam quickly to where the girl was, with her head only just above the water, was shouting for help. She was very frightened. When the lifeguard reached her, she struggled with him, as drowning people often did. However, he was a skillful lifeguard and quickly took hold of her and swam with her back to the beach. By the time he reached it, Mr. and Mrs. Gordon had realized what had happened. They had run down to the water's edge. Neither of them could swim. They just stood in the shallow water, and worried about their daughter. Had the lifeguard reached her in time? Fortunately, he had. “That was quick work, young man,” Mr. Gordon said. He turned to his wife, “Give the lifeguard a dollar.” “A dollar!” Sandra cried. “Dad, how can you give him a dollar! He saved my life. I was half dead.” “Quite right, girl,”Mr. Gordon said, pleased by his daughter's awareness of the value of money. He turned to his wife again and said, “She's right. She was only half dead. Give him fifty cents.”

    Whenever we're introduced to strangers, we make snap decisions about them according to our first impressions. Are they attractive or how much do they earn?

    For most Brits, simply asking someone how much they're worth' financially is considered very impolite. Thankfully, most people are kind enough to drop several hints (暗示)about their relative wealth or successful careers They always post on social media about flying to a meeting for work. They're always wearing clothes with labels big enough to silently scream about how rich they are and how well they're doing.

    It's a worrying trend, and I'm not immune to it. I've felt the warm happiness of knowing I earned more than somebody, and the baseless grey irritation of knowing that I earn less than another. I've checked into places while I know full well that anybody reading it will get jealous.

    It seems as though self-worth is increasingly being tied to the careers we choose and the money we earn. A study in 2013, for example found that nearly 17% of unemployed Americans were depressed compared to almost 6% of those who had a permanent job.

    We need to stop placing so much value on what a person earns. Don't get me wrong-being ambitious is not a fault, and achievements should always be celebrated. But when a person uses their success to judge you negatively it becomes a problem.

    If you want to know what you're really worth, here's a tip: It doesn't have anything to do with your bank account. It's about how many times you've been there for your friends. It's how many times you've been kind to a stranger It's every time you did something unselfish, or told your partner you loved him/her, or treated someone with respect no matter where they were in their own life.

    If English means endless new words, difficult grammar and sometimes strange pronunciation, you are wrong. Haven't you noticed that you have become smarter since you started to learn a language?

    According to a new study by a British university, learning a second language can lead to an increase in your brain power. Researchers found that learning other languages changes grey matter. This is the area of the brain which processes information. It is similar to the way that exercise builds muscles.

    The study also found the effect is greater when the younger people learn a second language. A team led by Dr. Andrea Mechelli, from University College London, took a group of Britons who only spoke English. They were compared with a group of "early bilinguals" who had learnt a second language before the age of five, as well as a number of later learners.

    Scans showed that grey matter density (密度) in the brain was greater in bilinguals than in people without a second language. But the longer a person waited before mastering a new language, the smaller the difference.

    "Our findings suggest that the structure of the brain is changed by the experience of learning a second language," said the scientists.

    It means that the change itself increases the ability to learn.

    Professor Dylan Vaughan Jones of the University of Wales, has researched the link between bilingualism and maths skills. "Having two languages gives you two windows on the world and makes the brain more flexible (灵活的)," he said. "You are actually going beyond language and have a better understanding of different ideas."

    The findings were matched in a study of native Italian speakers who had learned English as a second language between the ages of two and thirty-four. Reading, writing, and comprehension were all tested. The results showed that the younger they started to learn, the better. "Studying a language means you get an entrance to another world," explained the scientists.