Urban swans might be born with a daredevil gene that makes them less fearful of humans, compared with their rural colleagues.

    A study has found swans living in cities tend to be bolder and it is at least partly determined by a gene called DRD4. Birds with this gene could therefore be better adapted to settling in more populated areas, while more timid（胆怯的）swans would escape to less inhabited regions.

    It could help to explain why swans in public parks and on urban rivers have a reputation for being so aggressive towards humans - they are simply not afraid of us.

    Biologists from some universities in Australia, tracked and collected blood samples from black swans living in two wetlands near cities. One group of swans lived in a recreational urban park, while the other occupied a waste-water processing site out of town. The two areas were less than 20 miles apart. Later, from 2011 through 2013, the researchers started systematically scaring the swans at both sites. The researchers approached the birds and calculated how close they could get before they flew away. As expected, they noticed that while rural swans started flying away if a human was closer than 119 meters, the scientists could come as close to urban swans as 39 meters before taking off.

    Analyses of the blood samples, in fact, showed that 83 per cent of the less cautious swans presented the same genetic DRD4 variation（变异)while rural swans have different genetic makeups resulting in more wariness(谨慎，小心）.

The researchers conclude that swans with the bold variation of the gene might choose to live in urban environments, as they tend to be less bothered by human presence.

    Whenever we talk about holidays, my mother teases my sister and me about how we “make out like robbers.” She is referring to the fact that we are half Jewish and half Indian, so we receive gits on both the festivals of lights. Hanukkah and Diwali. Though my mother teases us, I do not mind getting two sets of gifts!

    Hanukkah is celebrated on the 25th day of the Jewish month. Which is usually sometime in December. On Hanukkah, like most Jewish families. We light a menorah and say a prayer each night. We also say a special prayer on the first night. After that, it is a tradition tor my sister and me to do 'hot and cold', for our hidden Hanukkah gifts. When we walk towards the gift, our parents say 'hot' and when we walk further away, they say 'cold'. We each receive one present every night of Hanukkah. Another part I like about this holiday is seeing family members who we do not see often. My aunt usually stays for a few days, and we sometimes visit other relatives.

    Diwali is celebrated on the 13th day of the dark fortnight of the month of Ashwin(October / November). To celebrate Diwali, my family does a pooja, or prayers, in honor of the goddess Lakshmi. Since she is the goddess of wealth and prosperity, the pooja includes washing silver coins in milk and water. In India, people decorate their houses with lamps, similar to the way you might light up your house for Christmas. My family just places a few candles outside We also set off firecrackers, which is my favorite part. We often do this activity with friends to add to the excitement.

    Both holidays have different histories and stories. We celebrate them in different ways, yet they both have the same meaning. They both translate into. Festival of Lights, and they both mean family and presents for me!

    Feeling blue about the world? “Cheer up.” says science writer Matt Ridley. “The world has never been a better place to live in, and it will keep on getting better both for humans and for nature.”

    Ridley calls himself a rational optimist—rational, because he's carefully weighed the evidence; optimistic, because that evidence shows human progress to be both unavoidable and good. And this is what he's set out to prove from a unique point of view in his most recent book, The Rational Optimist. He views mankind as a grand enterprise that, on the whole, has done little but progress for 100,000 years. He backs his findings with hard facts gathered through years of research.

    Here's how he explains his views.

    1) Shopping fuels invention

    It is reported that there are more than ten billion different products for sale in London alone. Even allowing for the many people who still live in poverty, our own generation has access to more nutritious food, more convenient transport, bigger houses, better cars, and, of course, more pounds and dollars than any who lived before us. This will continue as long as we use these things to make other things. The more we specialize and exchange, the better off we'll be.

    2)Brilliant advances

    One reason we are richer, healthier, taller, cleverer, longer­lived and freer than ever before is that the four most basic human needs—food, clothing, fuel and shelter—have grown  a lot cheaper. Take one example. In 1800 a candle providing one hour's light cost six hours' work.  In the 1880s the same light from an oil lamp took 15 minutes' work to pay for.  In 1950 it was eight seconds. Today it's half second.

    3) Let's not kill ourselves for climate change

    Mitigating (减轻) climate change could prove just as damaging to human welfare as climate change itself.  A child that dies from indoor smoke in a village, where the use of fossil­fuel (化石燃料) electricity is forbidden by well­meaning members of green political movements trying to save the world, is just as great a tragedy as a child that dies in a flood caused by climate change. If climate change proves to be mild, but cutting carbon causes real pain, we may well find that we have stopped a nose­bleed by putting a tourniquet (止血带) around our necks.

    Honey (蜂蜜) from the African forest is not only a kind of natural sugar, it is also delicious. Most people, and many animals, like eating it. However, the only way for them to get that honey is to find a wild bees' nest (巢) and take the honey from it. Often, these nests are high up in trees, and it is difficult to find them. In parts of Africa, though, people and animals looking for honey have a strange and unexpected helper—a little bird called a honey guide.

    The honey guide does not actually like honey, but it does like the wax (蜂蜡) in the beehives (蜂房). The little bird cannot reach this wax, which is deep inside the bees' nest. So, when it finds a suitable nest, it looks for someone to help it. The honey guide gives a loud cry that attracts the attention of both passing animals and people. Once it has their attention, it flies through the forest, waiting from time to time for the curious animal or person as it leads them to the nest. When they finally arrive at the nest, the follower reaches in to get at the delicious honey as the bird patiently waits and watches. Some of the honey, and the wax, always falls to the ground, and this is when the honey guide takes its share.

    Scientists do not know why the honey guide likes eating the wax, but it is very determined in its efforts to get it. The birds seem to be able to smell wax from a long distance away. They will quickly arrive whenever a beekeeper is taking honey from his beehives, and will even enter churches when beeswax candles are being lit.

    Qing-Feng Steamed Dumpling Shop. Daniang Dumpling. McDonald's. What do these companies have in common?

    Well, besides all being fast food chains, their logos are all red. And it's not a coincidence. Color is one of the many that companies use to connect with customers. And if fast food wasn't hard enough, those red logos might make it even harder to ignore.

    The average human can see ten million colors, but red is special. It's one of the first colors our ancient ancestors thought important enough to name. Early human languages were uncolorful. There were words for “black” and “white” and “red” but not much else.

    As a result, we have a deeper connection to red than any other color and we react to it in certain ways that actually play to fast food companies' advantage. For starters, researchers have found that red can cause a sense of urgency. On top of that, it also has an ability to whet (刺激) our appetites. And when you pair those two together, you've got the perfect recipe to attract hungry customers who want food, fast.

    So the red logo isn't just a welcoming sign. It's a seduction (诱惑) for your brain. Now, it's unclear why red makes us feel this way. But perhaps it has something to do with where the word comes from. Many ancient languages first named red from their word for “blood”. But red's bloody beginning has transformed. During medieval times, for example, red was worn by royals as a status symbol. And today, brides in many parts of India are married in red dress.

    In fact, red is one of the few colors today that cultures all over the world view positively. And it's no wonder companies attach so much importance to their logos. After all, we're a visual species. Despite having five senses, 80% of the information our brains process on a daily basis comes from our eyes. And according to marketing company WebPageFX, nearly 85% of consumers say the main reason they choose one product over the other is color.

    Just think what McDonald's would look like in blue, green, or pink! It's just not the same, right?

    Mr. Brown was a writer. He wrote many books, and he thought they were quite good. He lived in the city. One morning, he went to a small town near the city to visit a friend. He went there by bus. When he got to the town, he saw a bookshop not far from the bus stop. As it was early, he decided to go in and have a look. There were many books in the shop. He was very happy that all the books in the shop were written by him. "Where are other writer's books?" he asked the man in the shop. The man looked up at him and answered. "Oh, they are all sold out."