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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    Last summer, as part of my high school graduation project, I volunteered at Saunders House nursing home .I choose this experience because it was something that I had never done before and I wanted to lend a helping hand．At first it was challenging because I was extremely shy. My goal in volunteering was to bring a smile to the residents（住客） by doing different activities from word games to playing chess. I feel as if I had accomplished that goal.

    At the nursing home, I did a lot of different activities with the residents ranging from Jeopardy to Wheel of Fortune. One of my favorites was a word game where I would write a ten -letter word on the board and the residents would try to come up with as many smaller words as possible. I could tell that it was one of their favorite games because they always seemed to be so enthusiastic when they played．I also transported residents to and from their rooms when they needed help; and whenever it was a nice day out, I would take them outside to get some fresh air and relax. On Saturday mornings, I would deliver the newspaper to the residents and on Sundays, I assisted with morning church services.

    The most unforgettable part of this experience was when I had one-on-one conversations with the residents. It was incredible how many great stories they had to tell. Their stories were so interesting and the experience was unforgettable for me .

    Growing up in the mountainous Sierra de Penamayor, in Asturias, northern Spain, Aladino Montes had been shooting deer ever since he was a child, but his life as a hunter came to an abrupt end 10 years ago, when he met Bambi, an adorable deer that has remained by his side ever since. Aladino has never shot an animal since.

    53-year-old Aladino recalls driving through the mountains in his little jeep, ten years ago, when he saw a couple of cows being followed by a skinny little deer. Deer don't usually hang out with cows, so he approached the animals for a closer look. That's when he noticed that the deer had several wounds and would have probably died without proper medical care. He put the injured animal in his car and drove back to his house where he nursed it back to health. But instead of running back towards the forests, the deer stayed by Aladino's side. They've been best friends ever since.

    He always loved animals, but his father had taught him to hunt deer as a child. He did it for food, not sport, but ever since he adopted Bambi, he hasn't shot a single animal.

    Aladino's cabin sits at 1,140 meters above sea level, offering tourists a beautiful view of the surrounding mountainside. On clear days, one can see all of central Asturias all the way to Gijon, but most people don't travel to Les Praeres for the view, they come to see Bambi, the friendly deer.

    Sometimes, Bambi will walk straight into the bar in search of Aladino and leave everyone with their mouth open, or even let people pet her. But she's always most comfortable at the side of her rescuer. She's so relaxed around him that she makes other deer feel safe as well.

You might think people all over the United States have Wi-Fi—wireless Internet service—and mobile phones. But there is no such service in Green Bank, West Virginia, a tiny town four hours from the U.S. capital, Washington D.C. Fewer than 150 people live in Green Bank, which has two churches, an elementary school and a public library. It is also home to the largest radio telescope in the world.

    There is a ban on Wi-Fi in Green Bank, along with anything else that can create electromagnetic(电磁的)waves. Officials say the waves could disturb the signals the telescope receives.

For many Americans, a visit to Green Bank is a little like returning to the 1950s. To get there, you must read road signs—because there is no GPS service in the town. People can connect with the Internet through telephones, but wireless service is not allowed.

    The observatory(天文台)is one of the largest employers in the area. The federal National Science Foundation(NSF) spends about ＄8.2 million a year to operate the observatory, telescope and educational center.

    Jonah Bauserman is a technician. If he supposes there is signal that is not allowed in the zone, he drives to the house where the signal is coming from and checks it. But once a week, when the device is cleaned, some banned devices are allowed near it.

    People in the town respect the work of the scientists. And they say they are happy to live without Wi-Fi and mobile phones. “You know, instead of sitting here on our phones and other devices we're out fishing and hunting and going to each other's houses.” Everyone knows each other and communication is almost always face-to-face.

    Good health is the most valuable thing a person can have, but one cannot take good health for granted. It is important to remember that the body needs proper care in order to be healthy. There are three things that a person can do to help stay in good shape: eat right food, get enough sleep, and exercise regularly.

    Proper nutrition (营养) is important for good health. Your body cannot work well unless it receives the proper kind of "fuel"(燃料).Don't eat too much food with lots of sugar and fat. Eat plenty of foods high in protein (蛋白质) ,like meat, fish, eggs and nuts. Vegetables and fruits are very important because they provide necessary vitamins (维他命) and minerals. However, don't overeat. It is not helpful to be overweight.

    Getting the proper amount of sleep is also important. If you don't get enough sleep, you feel tired and easily get angry. You have no energy. Over a long period of time a little amount of sleep may even result in a change of personality (人的个性). Be sure to allow yourself from seven to nine hours of sleep each night. If you do, your body will feel strong and refreshed, and your mind will be sharp.

    Finally, get plenty of exercise. Exercise firms the body, strengthens the muscles, and prevents you from gaining weight. It also improves your heart and lungs. If you follow a regular exercise program, you will probably increase your life-span (寿命). Any kind of exercise is good. Most sports are excellent for keeping the body in good shapes: basketball, swimming, bicycling, running and so on are good examples. Sports are not only good for your body, but they are enjoyable and interesting, too.

    If everybody, were to eat the right foods, get plenty of sleep and exercise regularly, the world would be a happier and healthier place. We would all live to be much older and wiser.

By 11:00, Gopamma knew something was wrong. Her husband, Hanutha, should have returned from collecting firewood an hour before. Gopamma sent for her son, who gathered a search party and headed to Bandipur Tiger Reserve, a nearby national park in south-western India. Just inside the forest, they discovered Hanutha's half-eaten remains. The tiger that killed him was still sitting next to the body.

In the face of her husband's death, Gopamma struggled not only with grief but economic hardship. Her son had to drop out of university. "My life was much better when my husband was alive," she says. "My older son could have studied, but now both of my sons have to work. I feel insecure and dependent. "

Despite all this, Gopamma feels no hate toward the tiger that killed her husband. Like many Hindus in India, she views humans and creatures, each with an equal right to existence. Her husband's death, she says, has nothing to do with the fact that the government is trying to save tigers: "This was my fate."

Rural Indians are unique in the world for their high tolerance for co-existing with potentially deadly wildlife. "You don't find this in other cultures," says Ullas, a biologist at the Wildlife Conservation Society and a leading expert on tigers. "If this kind of thing happened in Montana or Brazil, they'd wipe out everything the next day. "

The country holds just 25% of total tiger habitat, but accounts for 70% of all remaining wild tigers, or around 3, 000 animals today. Success does not come without cost, however. They still have a lot of difficulties with tigers breaking into human-dominated places in certain parts of India, livestock(牲畜) are killed and sometimes so are people.

Some animal activists think that there are too few tigers left in the wild, so even one shouldn't be killed. Tigers are treasures, we'd better live with them together.