It seems that the great desire among the young is to be popular. The desire to be popular can force you into looking and acting like everyone else. You can lose yourself in a sea of identical hairstyles and thinking styles.

    I was forced to think about popularity not too long ago in a talk I had with my daughter. Margy had to change schools when my busy work schedule made it necessary for me to move houses. I suppose that, for a girl in her teens, entering a new school is like spending a season alone in the tropical jungles. At least that's how Margy found it at first. However, as the school year drew to a close, one student after another came to her. I told Margy that I would have been more concerned if she had been an instant social success in her new school. Nobody can please everyone. If you try to do so, you will find values as lasting as soap bubbles blown into the air.

    Some teenagers claim they want to dress as they please. But they all wear the same clothes. They set off in new directions in music. But somehow they all end up listening to the same record. Their reason for thinking or acting in a certain way is that the crowd is doing it. They have come out of their cocoon into a larger cocoon.

    I know that it has become harder for a young person to stand up against the popularity wave. Our way of life makes a young nonconformist stand out like a Martian. These days there's a great barrier for the young person who wants to find his or her own path. But the barrier is worth climbing over. You may want to listen to classical music instead of going to a party. Well, go to it. Be yourself. Popularity will come with the people who respect you for who you are. That's the only kind of popularity that really counts.

    Sometimes I really doubt whether there is love between my parents. Every day they are very busy trying to make money for my schooling.

    One day, my mother was sewing a quilt(缝被子). I silently sat beside her. "Mum, is there love between you and Dad?" I asked in a very low voice.

    With surprise in her eyes, she stopped her work for a while. Then she said, "Susan, look at this thread(线). It can hardly be seen, but it' s really there. It makes the quilt strong. If life is a quilt, love should be a thread. Love is inside. "

    I couldn' t understand her until the next spring. At that time, my father suddenly got sick seriously. My mother had to stay with him in the hospital for a month.

    After they were back, my mother helped my father walk slowly on the country road every day. They were so kind to each other and it seemed they were the happiest couple.

    After two months my father still couldn' t walk by himself. "Dad, how are you feeling now?" I asked him one day.

    "Susan, don' t worry about me," he said. "I just like walking with your mum. I like this kind of life." Reading his eyes, I knew he loves my mother deeply.

    Now I understand that love is just a thread in the quilt of our life. Love is inside, making life strong and warm.

    How the Grand Canyon (大峡谷) was created remains one of the geology's greatest mysteries. Some evidence suggests that the process was a gradual one in which the Colorado River (which runs through the canyon) slowly cut deeper and deeper into the ground over millions of years. But volcanic rock samples taken from the canyon now suggest that the canyon was down-cut instead.

    Down-cutting is when a flood of water rushes over a landscape (地形) with enough force to cut deeply into the ground and leaves behind a canyon. Such a flood is usually released when a natural or man-made dam (堤坝) bursts.

    Robert Webb, a research geologist, says natural dams seem to have formed and broken across the Colorado River several times during the last million years. The dams were built when lava(熔岩) from the eruptions of nearby volcanoes flowed into the river. The lava hardened into hard rocks and blocked the river, causing it to back up and form a lake. Each time the lake grew so huge that it broke the rock dam, releasing a flash flood that furthered the down-cutting process and deepened the canyon.

    Down-cutting is not just an earthly event. Satellite photos sent back from Mars suggest that the process has happened there, too, say many other researchers.

    The photos, taken by the Mars Global Surveyor, indicate that an enormous lake existed on Mars 3.5 billion years ago. The lake spilled into a large nearby hole. One edge of the hole broke, releasing a flash flood that quickly carved out a grand canyon.

    The existence of down-cutting on Mars is just one more piece of evidence that the cold, dry planet was once warm and wet.

    Oil is essential for modern life. About 64 percent of the world's oil is located in the Middle East, but the heaviest consumers of oil are Europe, America, and Japan. The problem lies in getting the oil from the countries that produce it to the countries that consume it. This is mainly done using oil tankers. Usually the oil is shipped safely and with no problems, but occasionally there is a disaster.

    Every year millions of tons of oil are spilled into the ocean. Although this is only a small percentage of the total amount shipped around the world each year, this spilled oil can have terrible effects on ocean life, including the coastlines where the oil washes up onto shore.

    One of the worst oil spills in history occurred along the Alaskan coastline in 1989, when the Exxon Valdez tanker ran aground off the coast of Alaska, spilling 42 million liters of oil. Although it wasn't the largest oil spill, the disaster was terrible because it occurred in such a sensitive natural area. In this spill, the tanker's captain, who was tired from overwork and drinking alcohol, had gone to take a rest. He gave control of the ship to another sailor, who was unfamiliar with the route. The ship ran onto Bligh Reef. Damaged by the reef, the ship leaked oil out into the ocean. More than 1,600 kilometers of coastline were affected by the oil spill. Many birds and otters died as a result of the oil covering their skin, and many other sea creatures and the animals that fed on them were also severely affected.

    In 1888 an Egyptian farmer digging in the sand near the village of Istabl Antar uncovered a mass grave. The bodies weren't human. They were feline — ancient cats that had been mummified(木乃伊化的) and buried in holes in astonishing numbers. "Not one or two here and there", reported English Illustrated Magazine, "but dozens, hundreds, hundreds of thousands, a layer of them, a layer thicker than most coal joints, ten to twenty cats deep. " Some of the linen-wrapped cats still looked presentable, and a few even had golden faces. Village children peddled the best ones to tourists for change; the rest were sold as fertilizer. One ship transported about 180,000, weighing some 38, 000 pounds, to Liverpool to be spread on the fields of England.

    Those were the days of generously funded explorations—that dragged through acres of desert in their quest for royal tombs, and for splendid gold and painted masks to decorate the estates and museums of Europe and America. The many thousands of mummified animals that turned up at religious sites throughout Egypt were just things to be cleared away to get at the good stuff. Few people studied them, and their importance was generally unrecognized.

    In the century since then, archaeology has become less of a treasure hunt and more of a science. Archaeologists now realize that much of their sites' wealth lies in the majority of details about ordinary folks—what they did, what they thought, how they prayed. And animal mummies are a big part of that.

    "They're really displays of daily life," says Egyptologist Salima Ikram. After peering beneath bandages with x-rays and cataloguing her findings, she created a gallery for the collection — a bridge between people today and those of long ago. "You look at these mummified animals, and suddenly you say, Oh, King So-and-So had a pet. I have a pet. And instead of being at a distance of 5,000-plus years, the ancient Egyptians become clearer and closer to us."

I was asked by a reader recently why so many animals seem to have pink ears，when their bodies are all different colours? The truth is that most animals actually don't have pink ears. Let us explain.

Near the equator (赤道), where the climate is hot, animals are likely to have darker skin, including on their ears. Think of the African elephant, which has quite dark ears. In colder climates, skin colour is usually lighter and often pink.

Why is skin colour different in different climates? Skin pigmentation, which is what gives skin its colour, can protect against sunburn and skin cancer. When animals live in colder parts of the world, they don't need it as much to survive. Light-coloured skin also helps animals stay warmer because it reduces heat loss, which is useful if you're in a colder climate.

For most animals, the colour of their fur or other body covering has generally developed as camouflage. That allows animals to mix into the background and avoid being eaten, or for predators (捕食者) to remain hidden during hunting. One example is the sandy-coloured coat of the desert fennec fox, which uses camouflage for both hunting and hiding.

By the way, in many animals, ears come in many different shapes and sizes. For example, in bats, the serval (a type of African wildcat) and the fennec fox, the ears are large compared to their body size—this helps them hear better because it allows them to sense more sound waves. Naked mole-rats have tiny ears because they need to dig a lot. Big ears would get in the way. The other downside of big ears is that you can lose a lot of body heat. That's why animals that live in really cold places, like the Arctic fox, have quite small ears.