Light travels at a speed which is about a million times faster than the speed of sound. In one second, light travels about 300,000 km, but sound travels only 344m. You can get some idea of this difference by watching the start of a race. If you stand some distance away from the starter, you can see smoke come from his gun before the sound reaches your ears. This great speed of light produces some strange facts. Sunlight takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light rays（光线）left the moon 1.3 seconds before they reached you. The nearest star is so far away that the light which you can see from it tonight started to travel towards you four years ago at a speed of nearly 2 million km per minute. In some cases the light from one of tonight's stars started on its journey to you before you were born.

    Thus, if we want to be honest, we cannot say “The stars are shinning tonight.” We have to say, “The stars look pretty. They were shining four years ago but their light has only just reached Earth.”

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It is OK not to be OK

    This is the simple encouragement people often use for themselves or others. But for professional athletes, this can be the hardest sentence to say.

    On March 6, Cleveland Cavaliers forward Kevin Love posted an article titled “Everyone is Going Through Something” on the website The Players' Tribune. In the article, the 29-year-old showed how he suffered from his first panic attack on Nov 5 in a game against the Atlanta Hawks and why he was so worried about sharing his story with the public.

    Love identified that what keeps people from speaking up about their mental health challenges is the fear that many people see them as a weakness. “Growing up, you figure out really quickly how a boy is supposed to act. You learn what it takes to 'be a man'. It's like a play book: Be strong. Don't talk about your feelings. Get through it on your own,” he wrote.

    And being an NBA player made his situation even more difficult. Love was afraid to share his struggles because he didn't want his Cavaliers teammates to think that he was unreliable.

    However, as it turned out, Love's teammates understood and supported him. Cleveland superstar LeBron James even wrote on social media that Love is “even more powerful now than ever before”.

    For Love, it was a journey of empowerment to accept and address his mental illness and share his experience with millions of people who face the same problems. In fact, he was inspired to talk about his situation by Toronto Raptors shooting guard DeMar DeRozan, who had also opened up about his mental health issues.

    Last month, the 28-year-old told the Toronto Sun that despite being a top-performing and wealthy NBA player, he still deals with constant blues. “It's one of the things that no matter how indestructible (坚不可摧的) we look like we are, we're all human at the end of the day, ”he said. “Sometimes…it gets the best of you, when everything in the whole world's on top of you, ” But other times, by admitting who we are, we can get what we want. As Love told Advance Ohio Media, “You have to let some of that stuff bleed out in order to fully recover from it.”

    LIANG TAO sold 80 pink Givenchy bags in 12 minutes. Becky Fang sold 100 Mini Cooper cars in just five. Both are wanghong, literally “red-hot on the web”. Every day millions of Chinese search social media for wanghong posts or tune in to live-streams for wanghong's opinions on everything. The fans are helping this new Chinese Internet star to make money out of their popularity—and to shake up the country's e-commerce industry in the process.

    A few of wanghong have been hired by luxury brands. Jaeger-LeCoultre, a Swiss watchmaker, hired Papi Jiang for a video ad targeting young urbanites (都市人), including her 27m fans on Sina Weibo, a Twitter-like microblog. Zhang Yi of iiMedia Research, a consulting firm, estimates that up to 15% of sales on shopping sites like Taobao or social-media apps such as WeChat are influenced by wanghong's public support. The length of a dress might be decided by a survey of a wanghong's fans; its launch date might be based on the number of hits, shares or comments it collects, some of which can cause last-minute design changes.

    This poses a new challenge for retailers(零售商), whose supply chains must respond ever more quickly to wanghong's opinions. Whereas previously a company would look for a celebrity to match its image, wanghong and their admirers are shaping goods.

    Another challenge comes directly from wanghong themselves. They increasingly make money not merely from online support or advice but by launching their own e-commerce stores. Sales of goods accounted for just under half of wanghong earnings of 53bn yuan ($8bn) in 2016, estimates Analysys, a Chinese market-research firm (the rest came mostly from live-show tips and adverts).

    Some wanghong are going a step further. In November Becky Fang launched her own clothing line. Part of her motivation, she says, was that the brands she supported did not always match the trends she was sharing with her followers. By creating her own brand, Becky's Fantasy, she have full control of the quality. She also gains a new income. For the time being only 3-5% of wanghong follow Becky Fang's example, iiMedia Research estimates. But it expects the model to become an industry in its own right, including entertainment and e-commerce, and driven by online data.

    Gardening is a very popular hobby. And it is one that produces wonderful results – food for your dinner table and flowers for your home! Gardens themselves can be very beautiful. So you would think that a garden path is a great place to be. Well, in conversation, it is not. Leading someone up the garden path means you are trying to trick them. You are not trying to show them your beautiful flowers.

    Speaking of beautiful flowers, gardeners love to see small buds (芽) forming on their plants. Besides plants and flowers, people can bud, too. If a child is good at drawing and painting, we can call him a budding artist. So “budding” describes something that is beginning to develop.

    On the opposite end, you stop something from growing if you nip it in the bud. This is a common expression when we talk about stopping something bad and preventing it from continuing. It's good to nip small problems in the bud before they turn into big problems.

    Now flowers that bloom （开花）are beautiful to see – even garden-variety flowers. “Garden-variety” describes anything that is common and not so special. You can have a garden-variety cold—not a serious illness.

    Now, a problem that many gardeners have is weeds. Weeds grow easily and can quickly take over a garden. In conversation, we sometimes use “weeds” to mean too many details. So, if you are in the weeds, you are taken over by too many details.

    As we said, weeds grow quickly. So do children. So, we like to say a child grows like a weed. This expression compares a child's fast growth to that of a weed.

    Shyness is the cause of much unhappiness for a great many people. Shy people are anxious and self-conscious; that is, they are concerned with their own appearance and actions too much. Negative thoughts are constantly occurring in their minds: What kind of impression am I making? Do they like me? Do I sound stupid? Am I wearing unattractive clothes?

    It is obvious that such uncomfortable feelings must affect people unfavorably. A person's self-concept is reflected in the way he or she behaves and the way a person behaves affects other people's reactions. In general, the way people think about themselves has a deep effect on all areas of their lives.

    Shy people, who have low respect, are likely to be passive and easily influenced by others. They need faith that they are doing "the right thing". Shy people are very sensitive to criticism. It makes them feel inferior（自卑）.They also find it difficult to be pleased by praises because they believe they are unworthy of praise. A shy person may respond to a praise with a statement like this one: "You're just saying that to make me feel good, I know it's not true.” It is clear that, while self-awareness is a healthy quality, overdoing it is harmful.

    Can shyness be completely got rid of, or at least reduced? Fortunately, people can overcome shyness with determination since shyness goes hand in hand with lack of self respect. It is important for people to accept their weakness as well as their strengths. Each one of us has his or her own characteristics. We are interested in our own personal ways. The better we understand ourselves, the easier it becomes to live up to our chances for a rich and successful life.

    Started in 1636, Harvard University is the oldest of all the many colleges and universities in the United States. Yale, Princeton, Columbia and Dartmouth were opened soon after Harvard.

    In the early years, these schools were much alike. Only young men went to colleges. All the students studied the same subjects, and everyone learned Latin, Greek and Hebrew. Little was known about science then, and one kind of school could teach everything that was known about the world. When the students graduated, most of them become ministers or teachers.

    In 1782, Harvard started a medical school for young men who wanted to become doctors. Later, lawyers could receive their training in Harvard's law school. In 1825, besides Latin and Greek, Harvard began teaching modern languages, such as French and German. Soon it began teaching American history.

    As knowledge increased, Harvard and other colleges began to teach many new subjects. Students were allowed to choose the subjects that interested them.

    Today there are many different kinds of colleges and universities. Most of them are made up of smaller schools that deal with special fields of learning. There's so much to learn that one kind of school can' offer it all.