Have you ever wondered when dogs first became “man's best friend” and the world's favourite pet? If you have then you're not alone. When and where dogs first began living side-side with humans are questions that have stirred hot debate among scientists. There are a few hard facts that all agree on. These include that dogs were once wolves and they were the first animal to be domesticated(驯养) by humans. They came into lives some 15000 years ago, before the dawn of agriculture.

    Beyond that, there is little agreement. The earliest bones found that are unquestionable dogs and not wolves date from 14,000 years ago. However, 30,000-year-old skulls have been discovered in France and Belgium that are not pure wolf and some scientists think could be dogs.

    With such puzzling evidence, many scientists are now turning to DNA to find out when and where dogs were first domesticated. In one research project, tens of thousands of blood samples have been taken from street dogs around the world. The plan is to compare them with those of wolves. It's even possible to analyse DNA from ancient bones. Tiny pieces of the 30,000-year-old skulls mentioned earlier are currently being studied, and another DNA study has already shown that ancient dogs preserved in the Alaskan ice-fields evolved from Asian wolves, not American ones.

    Indeed, the ancient DNA may turn out to be more informative than the DNA of living dogs. Because dogs have accompanied humans around the world for thousands of years, their current distribution may tell us very little of their origins. This is why different groups of scientists believe that dogs variously originated in eastern Asia, Mongolia, Siberia, Europe or Africa.

    But why were the animals domesticated in the first place? The most recent theory is that dogs domesticated themselves, initially living in and around our ancient villages to eat any food thrown out. Today, this is a way of life still shared by three -quarters of a billion unowned dogs worldwide.

    You may have seen a talking parrot on a TV show, in a movie, or even in someone's home. The parrot has learned to copy sounds that people make. Birds are not the only animals that can copy the noises they hear. Dolphins, bats, and some apes also copy sounds. Now we can add elephants to this list of copycats.

    Dr. Joyce Poole is a zoologist. She studies the sounds of elephants. While she was in Kenya, she would hear strange noises made by Mlaika after sunset. Mlaika was a 10-year-old African elephant.

    Mlaika lived near a highway. Dr. Poole says, “I could not tell the difference between Mlaika's call and the distant truck noise.” She and other scientists studied Mlaika's sounds. It turned out that Mlaika was copying the sounds of the trucks driving by. Why would Mlaika copy trucks that she heard going by on the highway? Animals that are able to copy sounds may enjoy practicing new sounds. When they are kept outside of their natural environment, they may copy unusual sounds. That may be why an elephant would copy the sound of a truck.

    “Mlaika was not the only copycat elephant,” Dr. Poole says. Calimero is a 23-year-old male African elephant. He spent 18 years with two female Asian elephants. Asian elephants make chirping sounds (sounds made by birds) to talk with one another. African elephants usually do not make chirping sounds. But Calimero now does. He is copying his Asian elephant friends. Dr. Poole says that elephants need to form bonds with their family and friends. She says, “They make sounds to communicate with each other. When they are separated, they use sounds to keep in contact.”

    Parrots, dolphins, humans, and elephants show that being a copycat is one way that animals and people make new friends and keep old ones.

    Having a great collection of books at home doesn't really mean that you are a person who loves reading. It may be got from your father or your father's father, and it can just impress people around you with the fact that you are a person of culture.

    From my point of view, reading is very important in our daily life. For example, reading is a way of gaining knowledge in different areas. It can help us have a great imagination, and it makes things easier when it comes to making compositions on different themes. It gives you the possibility to speak about science, even if you don't work in this field. You can express your opinions about a political event because you have read something about that.

    Secondly, reading gives us the possibility to enter the world of imagination. We can imagine what life will be like in the future. Sometimes, we compare ourselves with the people in the stories we read and they can give us some clues to solve the problems and tell us what to do in certain situations. Books are based on real life. Even if writers are considered to be somehow different from common people, they often face the same problems as we all do.

    In short, I would like to say that literature is the perfect way of enriching our culture, expressing correctly, having a rich vocabulary, being able to understand different fields and really being considered to be a learned person.

    Do you often lose things? Don't worry. Now a new tool, which can be connected to any object you might lose, may be the way to solve your problem. The Tile, a small square linked up to your iphone or ipad by means of Bluetooth, lets you see how close you are to your missing item, within a 50-to-150-foot range (范围). If the item goes out of your phone's 150-foot range, it can still be found on other smart phones with the same app.

    When you drive the app on your phone, it shows you, with green bars that increase or decrease, how close or far away you are from the Tile. You can also program it to make a sound when you get close to the Tile. And you can link up your phone with up to ten Tiles. And if your lost object — a dog, for example, or a stolen bike — go out of your own phone's 150-foot Bluetooth range, you can set it as a “lost item”. If any of the phones with the Tile app comes within range of your lost item, a message will be sent to your phone, telling you its position. The Tile app also has the function to remember where it last saw your Tile, so that you can easily find where you left it.

    Since the Tiles use Bluetooth rather than GPS, they are never out of battery or needn't to be charged, and they work for one year before needing to be replaced. And the app works with all generations of iPhones and iPads.

    For further information, please visit www. tile666.com.

    I had an old neighbor, a doctor named Gibbs. When Doctor Gibbs wasn't saving lives, he was planting trees. He had some interesting theories about planting trees. He hardly watered his new trees.

    Once I asked why and he told me that watering plants damaged them because it made them grow weaker. He said he had to make things difficult for the trees so that only the strongest could survive. He talked about how watering trees made them develop shallow roots and how, if they were not watered, trees would grow deep roots in search of water.

    So, instead of watering his trees every morning, he'd beat them with a rolled up newspaper. I asked him why he did that, and he said it was to get the trees' attention.

    Doctor Gibbs died a couple of years after I left home. Sometimes I walked by his house and looked at the trees I'd watched him plant 25 years ago. They were tall and strong.

    I planted several trees myself a few years ago. Two years of caring for these trees meant they grew up weakly. Whenever a cold wind blew, my trees trembled. Adversity seemed to benefit Doctor Gibb's trees in ways comfort and ease never could.

    Every night before I go to bed, I check on my two sons. I often pray that their lives will be easy. But lately I've been thinking that it's time to change my prayer. I know my children are going to experience difficulties. There's always a cold wind blowing somewhere. What we need to do is to pray for deep roots, so when the rains fall and the winds blow, we won't be torn apart.

    Many high school students consider a college education useless. Therefore, they choose not to go to college. If you're one of them, think again. Here are some reasons why you should go to college and receive a good education there.

    Schools and universities are the first sources of knowledge. We take that knowledge later on to build our careers after graduation. More knowledge will be gained after you start working, but without an education, that job will not be within easy reach. Knowledge leads to knowledge.

    While limited within the walls of the educational institutions, we openly explore other cultures of the world. We come to know that ours is not the only culture. Other cultures have valuable insights to share, enriching our own. Education also makes us want to travel and interact with various cultures, broadening our horizons.

    When there's a downturn (衰退) in the economy, those who attended college will be more likely to find a new job than those who only finished grade school and have a limited skills set. The more education you have, the more chances you will get to improve the quality of your life as you have a better job and earn a higher salary.

    When you're skillful and knowledgeable, you get to “rub knees” with people of similar backgrounds and tastes. It means a good education leads to excellent networking. Good networking can benefit you a lot in your later life.

    A good education makes you a more interesting person. You can talk about ideas and events instead of just other people and what's on sale in stores. An educated person doesn't gossip, having a preference to discuss ideas and listen to what other people have to say.