It is important to protect yourself from harmful rays. But if you think a high-factor sunscreen keeps you safe from harmful rays, you may be wrong. Research in this week's Nature shows that while factor 50 reduces the number of melanomas（黑瘤）and delays their occurrence, it can't prevent them. Melanomas are the most aggressive skin cancers. You have a higher risk if you have red or blond hair, fair skin, blue or green eyes, or sunburn easily, or if a close relative has had one. Melanomas are more common if you have periodic intense exposure to the sun. Other skin cancers are increasingly likely with long-term exposure.

    There is continuing debate as to how effective sunscreen is in reducing melanomas – the evidence is weaker than it is for preventing other types of skin cancer. A 2011 Australian study of 1,621 people found that people randomly selected to apply sunscreen daily had half the rate of melanomas of people who used cream as needed. A second study, comparing 1,167 people with melanomas to 1.101 who didn't have the cancer, found that using sunscreen routinely, alongside other protection such as hats, long sleeves or staying in the shade, did give some protection. This study said other forms of sun protection – no sunscreen – seemed most beneficial. The study relied on people remembering what they had done over each decade of their lives, so it's not entirely reliable. But it seems reasonable to think sunscreen gives people a false sense of security in the sun.

    Many people also don't use sunscreen properly applying insufficient amounts, failing to reapply after a couple of hours and staying in the sun too long. It is sunburn that is most worrying – recent research shows five episodes of sunburn in the teenage years increases the risk of all skin cancers.

    The good news is that a combination of sunscreen and covering up can reduce melanoma rates, as shown by Australian figures from their slip-slop-slap campaign. So if there is a heat wave this summer, it would be best for us, too, to slip on a shirt, use sunscreen and slap on a hat.

    We have to admit that many cities around the world today are heavily polluted. Careless methods of production and lack of consumer demand for environment friendly products have actually contributed to the pollution problem. One result is that millions of tons of glass, paper, plastic, and metal containers are produced and these are difficult to get rid of.

    However, today, more and more consumers are choosing “green” and demanding that the products they buy should be safe for the environment. Before they take action to buy a product, they ask questions like these “Will this shampoo add damage to the environment?” “Can this metal container be reused or can it only be used once?”

    A recent study showed that two out of five adults now take the environmental safety of a product into account before they buy it. This means that companies must now adjust the way they make and sell their products to make sure that they are “green” that is, friendly to the environment

    Only a few years ago, it was impossible to find green products in supermarkets, but now there are hundreds of them advocating green. In addition, some supermarket products carry labels (标签) to show that the product is green. Some companies have adopted the manufacturing (生产) of clean and safe products as their main selling point and emphasize it in their advertising.

    The concern for a safer and cleaner environment is making companies rethink how they do business. No longer will the public accept the old attitude of “Buy it, use it, throw it away, and forget it.” The public pressure is on, and gradually business is cleaning up its act.

    "Iris scan (虹膜扫描), please," the bank's computer voice tells you . You step up and the computer reads your eye, comparing it to the stored file it has of your iris. The images had better match—otherwise you won't be able to get your money.

    Iris scanning and other technologies, such as fingerprint and voice scanning, have appeared in many science fiction movies in the past. Today, these advanced technologies are part of the real world. They are common at work, the bank, the airport, and your local prison. The iris scan, fingerprint scan, and voice scan are all examples of biometrics( 生物测定学) a fast developing area of automatic personal identification technology . Basically, biometrics uses various ways to verify a person's identity, based on the individual's unique characteristics, including fingerprints, voices, irises, body heat patterns, facial images, handprints, signatures and so on.

    Biometrics identification systems have a number of advantages over password systems. The primary advantage is that an individual has to be physically present in order to be identified. Another important advantage is that there are no passwords to remember, forget, lose or steal.

    The voice scan is the simplest and most affordable form of biometrics. It only requires a computer, a microphone and the correct software. The software records a subject's voice and then compares it to a stored voice sample for identification purposes.

    For additional safety, fingerprint and handprint scans can also be employed. Fingerprint scans take the image of a fingerprint and compare it to a stored file of prints. Handprint scans identify the unique features of a hand.

    Iris scans currently give the highest level of accuracy among all the available biometrics systems. Another technology, full facial scans, is currently in use at border crossings and airports. Facial scanning equipment can actually track and identify moving faces within a crowd.

    The potential of biometrics is exciting and encouraging. With continued development, testing, and application, current technologies will become even more effective in the future. Soon, the days of password and car keys will be gone. Just don't leave home without your fingerprints!

    It was a morning in January. The jet stream (急流)had dipped down, causing the Arctic cold to reach the mountains of my home. It was only 2 degrees outside, but the cold wind made it feel like it was 15 below zero. Still, I was kneeling in the snow alongside my house trying to open a tiny door, so I eoukl get in. 1 had forgotten to leave my water dripping the night before and now my water pipes were frozen and my faucets(水龙头)were dry.

    The wind cut into me like a knife while I struggled to get two electric heaters in place around the section of frozen pipes. The waterlines were buried except for a small piece that connected up to my house. I put a heater on each side of it, ran the extension cords(软线)into my house and plugged them in. Both heaters roared to life and started blowing hot air on the frozen water pipes. My fingers had already started to go numb, so I stayed inside to wait. I could only hope that this bit of warmth could get my water flowing again. Finally, after twenty minutes, the water started flowing through my faucets again. I went back outside into the biller cold and gathered my heaters up. I looked at the weak January sun shining on the frozen snow and smiled. Then I sent a joy filled with "Thank you" heavenward and returned inside to make myself a hot breakfast.

    Sometimes the coldness of this life can get to us as well. It can make our hearts feel icy and frozen. It can keep our kindness and love from flowing out to others. Sometimes, though, all we need is a bit of warnth to get us going again. It can be a simple smile, a kind word, a heart-felt hug, a morning sunrise, a bird's song or any gentle reminder of just how much God loves us. Let us all be grateful for those bits of warmth that gel us going again. And let us all try to be that bit of wannth for others every chance we get.

    Have you ever been into a cave? If not, please follow us and explore some of the most beautiful caves from around the world!

    Marble Caves

    Located in the center of Lake General Carrera, the Marble Caves in Chico, Chile, are only accessible by boat. The surrounding crystal clear waters allow visitors to see the rock formations beneath them while the rock ceilings above change color(depending on the writer levels and the season). The best time to visit: during sunrise and sunset, when the sun's rays light up the cave walls, making it an experience to remember.

    Reed Flute Cave

    Reed F1ute Cave known as "the Palace of Natural Arts" is located in the northwest of Guilin in southern China. The limestone cave offers a grand fairyland of stalactites(钟乳石), stone pillars, stone curtains, birds, plants and animals in fantastic shapes and colors.

    Fingal's Cave

    This incredible sea cave is located on the uninhabited island of Staffa in Scotland. The cave's size, shape, and naturally­arched(拱形的) roof combine with the waves to create strange sounds that enhance its cathedral­like atmosphere.

    The Blue Grotto

    The Blue Grotto is the symbol of Capri. It is a sea cave found on the coast of the island and is a well-known spot to all who visit the area. This cave is unique for its brilliant blue light which comes from two sources: the entrance to the cave and a bigger hole beneath the entrance. When viewed from inside the cave, the entrance appears as a brilliant white light just above the waterline, while the underwater hole, which is the larger source of light, provides a blue light.

Tales From Animal Hospital David Grant

    David Grant has become a familiar face to millions of fans of Animal Hospital. Here Dr Grant tells us the very best of his personal stories about the animals he has treated, including familiar patients such as the dogs Snowy and Duchess, the delightful cat Marigold Serendipity Diamond. He also takes the reader behind the scenes at Harmsworth Memorial Animal Hospital as he describes his day, from ordinary medical check-ups to surgery. Tales From Animal Hospital will delight all fans of the program and anyone who has a lively interest in their pet, whether it be cat, dog or snake!

    £14.99 Hardback 272pp Simon Schuster

    ISBN 0751304417

    Isaac Newton: The Last Sorcerer Micheal White

    From the author of Stephen Hawking: A Life in Science, comes this colorful description of the life of the world's first modern scientist. Interesting yet based on fact, Michael White's learned yet readable new book offers a true picture of Newton completely different from what people commonly know about him. Newton is shown as a gifted scientist with very human weaknesses who stood at the point in history where magic ended and science began.

    £18.99 Hardback 320pp Fourth Estate

    ISBN 1857024168

     Fermat's Last Theorem Simon Singh

    In 1963 a schoolboy called Andrew Wiles reading in his school library came across the world's greatest mathematical problem: Fermat's Last Theorem ( 定 理 ). First put forward by the French mathematician Pierre de Fermat in the seventeenth century, the theorem had baffled and beaten the finest mathematical minds, including a French woman scientist who made a major advance in working out the problem, and who had to dress like a man in order to be able to study at the Ecole Polytechnique. Through unbelievable determination Andrew Wiles finally worked out the problem in 1995. An unusual story of human effort over three centuries, Fermat's Last Theorem will delight specialists and general readers alike.

    £12.99 Hardback 384pp Fourth Estate

    ISBN 1857025210