Eyesight（视力） plays a very important role in our daily life. Every waking moment, the eyes are working to see the world around us. Over forty percent of Americans worry about losing eyesight, but it's easy to include steps into our daily life to ensure healthy eyes. Here are five suggestions for a lifetime of healthy eyesight：

    Schedule（安排）yearly exams(检查). {#blank#}1{#/blank#} Experts advise parents to bring babies 6 to 12 months of age to the doctor for a careful check. The good news is that millions of children now can have yearly eye exams and following treatment, including eyeglasses.

    Protect against UV rays (紫外线). Long－term stay in the sun creates risk to your eyes. No matter what the season is, it's extremely important to wear sunglasses. {#blank#}2{#/blank#}

    Give your eyes a break. Two－thirds of Americans spend up to seven hours a day using computers or other digital products. {#blank#}3{#/blank#} Experts recommend that people practice the 20/20/20 rule: every 20 minutes, take a 20－second break and look at something 20 feet away.

    {#blank#}4{#/blank#} As part of a healthy diet, eat more fruits and vegetables each day. Vitamins (维生素) C and E help protect eyesight and promote eye health.

    Practice safe wear and care of contact lenses (隐形眼镜). Many Americans use contact lenses to improve their eyesight. While some follow the medical guidance for wearing contact lenses, many are breaking the rules and putting their eyesight at risk. {#blank#}5{#/blank#} Otherwise, you may have problems such as red eyes, pain in the eyes, or a more serious condition.

A．Eat your greens.

B．Eye care should begin early in life.

C．They can properly protect your eyes.

D．Stay in good shape by taking more vitamins.

E．Parents usually don't care about their own eyesight.

F．Always follow the doctor's advice for appropriate（适当的）wear.

G. This frequent eye activity increases the risk for eye tiredness.

    Neuroscientists have explained the risky, aggressive or just plain baffling behavior of teenagers as the product of a brain that is somehow compromised. Groundbreaking research in the past 10 years, however, shows that this view is wrong. The teen brain is not defective. It is not a half-baked adult brain, either. It has been forged by evolution to function differently from that of a child or an adult.

    The most important of the teen brain's features is its ability to change in response to the environment by modifying the communication networks that connect brain regions. It allows teenagers to make enormous progress in thinking and socialization. But the change also makes them sensitive to dangerous behavior and serious mental disorders.

    The most recent studies indicate that the riskiest behaviors arise from a mismatch between the maturation of networks in the limbic system(边缘系统), which drives emotions at adolescence, and the maturation of networks in the prefrontal cortex（前额皮质）, which occurs later and promotes sound judgment and the control of impulses. Indeed, we now know that one's prefrontal cortex continues to change noticeably until his 20s. And yet adolescence seems to be starting earlier, extending the “mismatch years.”

    The plasticity of networks linking brain regions—and not the growth of those regions, as previously thought—is key to eventually behaving like an adult. Understanding that, and knowing that a widening gap between the development of emotional and judgment networks is happening in young people today, can help parents, teachers, counselors and teenagers themselves. People will better see that behavior such as risk-taking and turning away from parents and toward peers are not signs of cognitive or emotional problems. They are a natural result of brain development, a normal part of adolescents learning how to negotiate with a complex world.

    The same understanding can also help adults decide when to intervene. A 15-year-old girl's departure from her parents' tastes in clothing, music or politics may be a source of anxiety for Mom and Dad but does not indicate mental illness. A 16-year-old boy's tendency to skateboard without a helmet or to accept risky dares from friends is not unimportant but is more likely a sign of short-range thinking and peer pressure than a desire to hurt himself. Knowing more about the unique teen brain will help all of us learn how to separate unusual behavior that is age-appropriate from that which might indicate illness. Such awareness could help society reduce the rates of teen addiction, motor vehicle accidents and depression.

    If you will be cycling, you will need to know what these traffic signs and signals mean.

    A sign like this one means that there is a bike lane（道）. If there is a bike lane, you are required to use it. If there is not a bike lane, you should ride with traffic as far to the right side of the road as possible.

    When the signal light turns green, cars go. When you cross the street at a signal light, you should wait for the walk signal. Be sure to look carefully to the left, right and left again, before crossing the street.

    When the signal light turns yellow, car drivers should slow down and prepare to stop. You should not cross if the light is yellow. The light is about to turn red, and cars will enter the intersection(十字路口).

    This signal is the WALK sign. It has a picture of a person walking instead of using the word WALK.

    This signal is the DON'T WALK sign. It is part of the signal with the picture of a person walking. This is a picture of a red hand, meaning you should stop. You should wait to cross the street until the green picture of the person walking is showing.

    Car drivers and bikers must come to a complete stop at STOP signs.

    A yield sign means to slow down and be ready to stop. If there are pedestrians（行人）or vehicles in or nearing the intersection, you must stop. If there is no traffic in or nearing the intersection and it is safe, you may go through.

    This sign means you are coming to a crosswalk. Car drivers and bikers must stop to allow people in the crosswalk to cross the street.

    STA Travel, the world's largest students and youth travel agency, beats any price! Every day we're working with our partners around the globe to get you (students, teachers and anyone under 26) the cheapest and most comfortable flights and top-rated accommodations. This part of www.statravel.com provides great tips for green travel — how to pack, how to leave your house or apartment, and how to plan for your trips. You'll also find a great selection of green travel adventure trips to all corners of the world.

    Green travel means responsible (负责任的) travel! Leave as little influence as possible on the places you visit and protect the environment both at home and during your trip. Think “Green” when you pack and when you travel. You'll help prevent long-term effects on the communities you leave and visit! Here's some advice on how to do that.

    Before you leave

    Turn your water heater to its lowest setting.

    Turn off your water from the outside.

    While you travel

    Pack suitable clothes in your luggage, none of which is to harm the environment.

    Try products made from recycled materials.

    Don't buy souvenirs produced from endangered species.

    Carry a reusable bottle for water and refill it as you go.

    Use the bathroom in the airport, NOT on the plane. The fuel used for a single flush (冲洗) could run a car for six miles.

    There is some unwelcome news for students preparing for exams and officers putting in long hours—you don't need that "refreshment（提神） break" as much as you may think.

    Scientists believed it was not easy for people to continue their work if they felt the need to have a snack or a rest to make them feel better. They argued that the only way to regain willpower is by supplying more energy to our bodies with rest, food or entertainment.

    But psychologists have challenged this theory, saying weak willpower is in your head. They found that a person's mindset(理念) and belief about willpower determine how long and how well they'll be able to work on a tough mental exercise. "If you think of willpower as something that's limited, you're more likely to be tired when you perform a difficult task," said Professor Veronika Job. "But if you think of willpower as something that is not easily depleted, you can go on and on."

    The researchers led by Mr. Job designed an experiment to test the students' beliefs about willpower. After a tiring task those who believed or were led to believe that willpower was a limited resource performed worse on standard concentration tests than those who thought of willpower as something they had more control over.

    Mr. Job said, "Students who may already have trouble studying are being told that their powers of concentration are limited, and they need to take frequent breaks. But a belief in willpower as a non-limited resource makes people stronger in their ability to work through challenges."

    The findings could help people who are battling with temptation(诱惑): people following strict diets and doing exercise regularly to lose weight, people trying to overcome addictions, employees facing a tight deadline. Willpower isn't driven by a biologically based process as much as we used to think.

    Right now, I am looking at a shelf full of relics, a collection of has-beens, old-timers, antiques, fossils. Right now, I am looking at a shelf full of books. Yes, that's right. If you have some spare cash (the going rate is about $89) and you are looking to enhance your reading experience, then I highly suggest you consider purchasing an e-reader. E-readers are replacing the books of old and I welcome them with open arms (as you should).

    An e-reader is a device that allows you to read e-books. An e-book is a book-length publication in digital form, consisting of text, images or both, and produced on, published through and readable on computers or other electronic devices. Sometimes the equivalent of a conventional printed book, e-books can also be born digital. The Oxford Dictionary of English defines the e-book as "an electronic version of a printed book", but e-books can and do exist without any printed equivalent.

    E-readers put printed books to shame. E-readers are superior to printed books because they save space, are environmentally friendly and provide helpful reading tips and tools that printed books do not.

    The average e-reader can store thousands of digital books, providing a genuine library at your fingertips. What is more, the e-reader itself is very small. It is easy to hold and can fit in a pocketbook or briefcase easily. This makes handling wooden giant such as War and Peace and Anna Karenina a breeze. Perhaps the only drawback to the space-saving aspect of an e-reader is that it requires you to find new things to put on your shelves.

    In addition, e-readers are environmentally friendly. The average novel is about 300 pages long. So, if a novel is printed 1000 times, it will use 300,000 pieces of paper. That's a lot of paper! And for the super bestsellers, these figures increase dramatically. For example, the Harry Potter book series has sold over 450 million copies. That's about 2 million trees! Upon viewing these figures, it is not hard to grasp the severe impact of printed books on the environment. Since e-readers use no trees, they represent a significant amount of preservation in terms of the environment and its resources.

    Finally, e-readers provide helpful reading tips and tools that printed books do not. The typical e-reader allows its user to adjust letter size, letterform and line spacing. It also allows highlighting and electronic bookmarking.

    Furthermore, it grants users the ability to get an overview of a book and then jump to a specific location based on that overview. While these are all nice features, perhaps the most helpful of all is the ability to get dictionary definitions at the touch of a finger. On even the most basic e-reader, users can find instant definitions without having to hunt through a physical dictionary.

    It can be seen that e-readers are superior to printed books. They save space, are environmentally friendly and provide helpful reading tips and tools that printed books do not. So what good are printed books? Well, they certainly make nice decorations.