As the population of the planet increases, so does the number of homes, business, parking lots, schools, airports and roadways. All these structures use electricity and need to be lighted. Humans demand light. They want their homes more comfortable and they want their streets safe. The problem is that researchers are finding that all the light is having a negative effect on humans and wildlife as well.

    Less than 10 years ago I drove to a thinly populated section of my own, lay down in the middle of the road and watched an attractive meteor shower(流星雨). If I did that today, I wouldn't be able to see the meteor shower.

    Nowadays scientists are finding light pollution can be almost as bad as carbon dioxide （二氧化碳）pollution. One of the saddest parts of light pollution is that most of it is unnecessary and most of the outdoor light that we use is wasted. One only needs to look at a row of street lights to see how much of the lights shines upwards and lights the sky: a total waste of electricity.

    Additionally, the production of electricity creates pollution by releasing greenhouse gases. This affects the air we breathe and our quality of life.

    Scientists are also studying the effects of light pollution on wildlife. Thousands of birds die each year when they crash into highly lighted buildings, as they become puzzled by the light. It has been long known that tiny baby sea turtles become lost and follow the light on the shore instead of heading towards the sea.

    Fortunately, light pollution is one of the easiest sources of pollution that can be corrected without a negative effect. Following some guidelines and a little searching on Google can give you many ideas on how to reduce your contribution to light pollution.

How to Enjoy Life As a Teen

    The "best years of your life"? Maybe not, but you can learn to make the most of your high school days.

    Learn to appreciate small things. Whether it's having a computer, having friends, having a good supply of food, a bed to sleep on, family that loves you, having a decent education or simply being born in this world, value it. {#blank#}1{#/blank#} Be happy, and life will reward you. Remember that these are the last few years you will be able to enjoy yourself without having to worry about the responsibility of an adult, but make sure you prepare yourself for when you do become one. When you actually become an adult, you'll learn to love that responsibility and you probably never want to go back.

    Choose your friends wisely. Unlike what many articles state, you don't have to be popular and have a gazillion friends to be happy. {#blank#}2{#/blank#} Try to have friends that like you who you are, not just because you are wearing a certain brand of shoes or something like that. These are people who shop at the same store as you; not someone who will sympathize with you when your dog dies.

    Keep your grades up. {#blank#}3{#/blank#} This also sets you up to get into a college you want to go to, which in turn prepares you for a career you will enjoy, improving your quality of life in the future. You'll get cheap car insurance as well if you have at least a B or A average.

    {#blank#}4{#/blank#} Participating in clubs, activities, and sports increases your chances of meeting new friends. While you only need 4 or 5 close friends, that doesn't mean you shouldn't try to meet new people. Participating gives you something to do instead of sitting bored at home and wallowing in self-pity.

    Work at a job you can enjoy. Working is a great way co gain experience and to meet other people. {#blank#}5{#/blank#} This will look great on your resume. If you can't find work, especially in this hard economic time, volunteer or make your own job.

A. Be sociable.

B. Remember the point of life is for you to enjoy it.

C. Find a hobby that is meaningful or practical.

D. In fact, many of the "friends" you have when you are popular are not true friends.

E. When you do get out of college, interviewing companies will look at your previous work experience.

F. Even though you want to enjoy your teen life as best as possible, don't idle away your time in school.

G. There is nothing more satisfying than seeing your hard work pay off in the form of A's and B's (but mainly A's).

    When I was 16 years old, I made my first visit to the United States. It wasn't the first time I had been abroad. Like most English children I learned French at school and I had often been to France, so I was used to speaking a foreign language to people who didn't understand English. But when I went to America I was really looking forward to having a nice easy holiday without any language problems.

    How wrong I was! The misunderstanding began at the airport. I was looking for a public telephone to give my American friend Danny a ring and tell her that I had arrived. A friendly old man saw me looking like being lost and asked if he could help me.

    “Yes,” I said. “I want to give my friend a ring.”

    “Well, that's nice,” he said. “Are you getting married? But aren't you a bit young?”

    “Who is talking about marriage?” I replied. “I just want to give my friend a ring to tell her I've arrived. Can you tell me where there's a phone box?”

    “Oh!” he said. “There's a phone downstairs.”

    When at last we did meet up, Danny explained the misunderstanding to me.

    “Don't worry,” she said to me. “I had many difficulties at first. There are lots of words which the Americans use differently in meaning from us British. You'll soon get used to all the funny things they say. But most of the time British and American people can understand each other!”

    You may have heard adults say they are uncomfortable in the morning without a cup of coffee. One reason they may feel that way is that coffee contains caffeine(咖啡因). Caffeine appears naturally in coffee, tea, and cocoa beans, which are used to make chocolate. But now food makers are adding it to many products, from potato chips to water.

    The US government is especially worried about the problem. That's why the Food and Drug Administration (FDA) is studying the health effects of caffeine on young people. Studies show that too much caffeine can make people nervous and unable to sleep. What's more, caffeine is habit- forming. Those who consume it regularly and stop suddenly may experience headaches and feel tired.

    One of the biggest concerns is the large amount of caffeine added to so-called energy drinks, like Red Bull. A 12-ounce can of cola has about 35 milligrams of caffeine. A similar serving of Red Bull contains more than three times that amount.

    The Institute of Medicine is also working on caffeine-safety measures. "Teenagers should not drink beverages that contain caffeine. They should be aware of caffeine's effects on health and on how the brain works. Take, for example, teenagers who consume caffeine to stay awake and study for a test. They will remember less of what they just studied," said Stallings, a member of the institute.

    Companies that make products with added caffeine claim they do not advertise them to kids. However, there is no law to stop children from buying them. So the FDA needs to set limits on caffeine, especially in energy drinks. As for added caffeine in foods, the government should just say no. If not, the amount of caffeine should be printed on food labels to remind consumers. The government must do that.

    Doctors say kids should avoid caffeine. If you need extra energy, try these natural boosters: eat right, exercise, and get plenty of sleep.

    When I was five or six years old, I remember watching TV and seeing other children suffer in other parts of the world. I would say to myself, "When I grow up, when I can get rich, I will save kids all over the world."

    At 17, I started my career here in America, and by the age of 18, I started my first charity organization. I went on to team up with other organizations in the following years, and met, helped, and even lost some of the most beautiful souls, tern six-year-old Jasmina Anema who passed away in 2010 from leukemia (白血病), whose story inspired thousands to volunteer as donors, to 2012 when grandmother lost her battle with cancer, which is the very reason and the driving force behind the Clara Lionel Foundation( CLF). We're all human. And we all just want a chance: a chance at life, a chance in education, a chance at a future, really. And at CLF, our mission is to impact as many lives as possible, but it starts with just one.

    People make it seem too hard to do charity work. The truth is, you don't have to be rich to help others. You don't need to be famous. You don't even have to be college-educated. But it starts with your neighbor, the person right next to you, the person sitting next to you in class, the kid down the block in your neighborhood. You just do whatever you can to help in any way that you can. And today, I want to challenge each of you to make a commitment to help one person，one organization，one situation that touches your heart. My grandmother always used to say, "If you've got a dollar, there's plenty to share."

    A mixture of deep sorrow and anger has swept Brazilians across the country — particularly in the city of Rio de Janeiro — with the burning of their beloved Museu Nacional, or National Museum.

    By Monday morning, when I visited the site, the firemen were busy trying to enter the huge, early 19th-century neoclassical building. For all we know, everything may have been burned to ashes. Fortunately, no one, not even the four security guards who witnessed the beginning of the fire, has been injured.

    Nobody yet knows the cause of the fire, but it is the officials' irresponsibility and the funding shortages in particular, which are being blamed for this tragedy.

    Some of the museum's researchers told the press that they had been able to save some things from the exhibition rooms before the fire moved in. However, we Brazilians have lost much of the material memory of our short past. A good part of our 518 years of history, or that which had been transformed into storable objects, disappeared in just a few hours.

    The people of Rio de Janeiro were fond of taking their children  or grandchildren to the museum to show off their knowledge of the odd-looking mummies brought in from Egypt by the Emperor Dom Pedro II, a huge skeleton of a humpback whale, or the brightly coloured feathers of a headdress of the Kayapo tribe.

    When I think that I can no longer take my youngest daughter to the Museu Nacional — that is what gets me emotional. It is this feeling that has penetrated (穿透) our souls and may leave Brazilians feeling empty for a long time to come.