Living in the wild can be hard. Finding food and staying safe aren't easy. Each day, animals struggle to survive in their habitats. Not all animals get by on their own. Some animals form a close partnership with other kinds of animals. These pairings are called symbiotic (共生的) relationships.

    In a symbiotic relationship, the animals depend on each other. One animal helps the other meet its needs. Sounds good, right? Not always. Some animals are not very kind to their partners. In some cases, one animal meets its needs but hurts its partner. Take ticks, for example. These insects suck blood to live. To get blood, they attach themselves to other kinds of animals. Ticks can pass germs that cause disease instead of helping their hosts.

    In other relationships, animals don't treat their partners so poorly Both animals benefit from living with the other animal.

    Small animals called cleaner shrimps have found a way of helping fish at coral reefs. As their name suggests, the shrimps clean the fish. They hang out at what scientists call a cleaning station. A fish stops by. Then a shrimp climbs onto the fish and even steps into the fish's mouth. The shrimp uses its tiny claws to pick stuff off the fish's body. That can include dead skin, tiny pieces of food, and wee creatures that can hurt the fish. The fish gets a nice cleaning. The shrimp enjoys a tasty meal offish trash.

    Small birds called plovers are also in the cleaning business. They have big customers—crocodiles. Crocs have long snouts（鼻子）filled with sharp teeth, Cleaning them is tricky. When a croc opens its mouth, the plover hops right in. The croc does not snap its snout shut. Instead, it lets the plover eat small, harmful animals attached to its teeth. The plover gets an easy meal while the croc gets clean teeth.

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The National Gallery

Description：

    The National Gallery is the British national art museum built on the north side of Trafalgar Square in London. It houses a diverse collection of more than 2,300 examples of European art ranging from 13th-century religious paintings to more modern ones by Renoir and Van Gogh. The older collections of the gallery are reached through the main entrance while the more modern works in the East Wing are most easily reached from Trafalgar Square by a ground floor entrance.

Layout：

    The modern Sainsbury Wing on the western side of the building houses 13th- to 15th-century paintings, and artists include Duccio, Uccello, Van Eyck, Lippi, Mantegna, Botticelli and Memling．

    The main West Wing houses 16th-century paintings, and artists include Leonardo da Vinci, Cranach, Michelangelo, Raphael, Bruegel, Bronzino, Titan and Veronese.

    The North Wing houses 17th-century paintings, and artists include Caravaggio, Rubens, Poussin, Van Dyck, Velazquez, Claude and Vermeer．

    The East Wing houses 18th- to early 20th-century paintings, and artists include Canaletto, Goya, Turner, Constable, Renoir and Van Gogh.

Opening Hours：

    The Gallery is open every day from 10 am. to 6 pm. (Fridays 10 am. to 9 pm.) and is free, but charges apply to some special exhibitions.

Getting There：

    Nearest underground stations: Charing Cross (2-minute walk), Leicester Square (3-minute walk), Embankment (7-minute walk), and Piccadilly Circus (8-minute walk).

    At Beaver Meadows Ranch on Red Feather Lakes, Colorado, there is a long list of outdoor winter activities for the entire family. Take a winter vacation there.

    Ice Fishing

    For $10 a day, visitors can try their hand at ice fishing. Ice fishing is available from 9:30 a.m. to 4 p.m. seven days a week. You will need to bring your own ice fishing equipment because it cannot be rented. You will need to have your fishing license too. For more about it, call 800-462-5870.

    Hot Chocolate & Cookies Sleigh Ride

    Passengers take a 15- to 20-minute sleigh ride through beautiful Colorado country. During the sleigh ride, you'll have the experience of stopping at an old-time cabin, warming yourself by a fire and eating cookies while drinking hot chocolate. You will need to contact them at 970-231-1955 to set up a time for your sleigh ride.

    Winter Horseback Riding

    Experience winter horseback riding while viewing the breathtaking beauty of the surrounding 840 acres where Beaver Meadows Ranch makes its home. You'll be guided on a tour by one of the expert wranglers (牧马人) when the weather permits. One-hour rides cost $35 per person and two-hour rides cost $50. For more information, contact them at 866-881-7679 to set up your horseback riding winter activity.

    Other Winter Activities Information

    For more information about Beaver Meadows Ranch, or if you'd like to book a room for an adventurous holiday, call 970-881-2450. It's not very often you can find a one-stop adventure spot full of winter activities. Take advantage of your free time this winter season and enjoy the outdoor scenery in Colorado.

    The koala is an unusual creature. Native to Australia and a bit bigger than a rabbit, it spends most of its time in eucalyptus trees（桉树）, feeding on leaves that are poisonous to nearly every other animal on the planet.

    The koala sleeps about 22 hours a day and spends the remainder of its time eating and resting. It might spend 10 minutes a day moving, experts say, usually from one tree to another. It has a soft pad at the end of its spine and extra thick fur on its rear end to make the effort, of sitting more comfortable.

    Threats and protective measures

    The unique lifestyle of the koala has helped it prosper, but today the cute and iconic creature is facing threats from habitat loss, disease and a changing climate. Koala populations are expected to decline by 50 percent in the next 20 years according to the Australian Museum.

    To help protect these animals, which bring in an estimated $1.1 billion to Australia each year through koala-related tourism, an international team of researchers has published the first complete genome（基因组）of the koala. Their hope is that the keys to the marsupial's（有袋动物）long-term survival might be planted in its genetic code.

"The ultimate goal is that we won't have to…rescue them from the edge of extinction," said Rebecca Johnson of the Australian Museum Research Institute in Sydney, who led the work.

    "Now we have a really good understanding of the koala genome, and we are in a fantastic position to use that knowledge to help us manage them."

    Early findings

    An elementary analysis of the koala's genome, published in Nature Genetics, has already yielded some interesting findings.

    For example, the authors found that, compared to other mammals, the koala's DNA includes an expansion in the number of genes that encode for enzymes involved in anti-poison. That allows them to have a diet that depends almost entirely on eucalyplus leaves which are unusually high in poison. However, it also means that koalas metabolize（代谢）medicines like anti-chlamydia antibiotics faster than other animals.

    The koala genome also revealed why koalas are such famously picky eaters. They are known to consume leaves from just 20 of Australia's 60 known eucalyplus species. And even when they are in one of their preferred trees, koalas take leaf selection very seriously.

    Information waiting to be discovered

    Johnson said that the information encoded in the koala's DNA is already being included in management strategies by conservation groups. However, she said the findings described in the new paper represent the early stages of what can be gleamed from the marsupial's genome.

    "The data is public, and I would love for anyone to start mining it and see what other amazing things they can find," she said." Once you have a genome of this quality, the sky's the limit with what you can do with it."

    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."

Not only is second-hand shopping good for the planet and your wallet, but new research finds that the more conscious(关注的) of style you are, the more likely you are to shop for second-hand clothes.

It is often assumed that those who shop for second-hand clothes do so to save money or reduce their impact on the environment. In fact, according to the research. style-consciousness is a bigger predictor of second-hand shopping than frugality or eco-consciousness.

Style-consciousness is very different from fashion-consciousness. Fashion is all about the "new" , and is constantly evolving. Style, on the other hand, is about expressing long-term individual identity.

Fashion shoppers are used to a continuous supply of new trends and fast fashion products. Fast fashion works quickly to replicate ( 复制) an ever-moving stream of fashion trends, generating large volumes of low-quality clothes. The impact of fast fashion on the environment is significant and well-documented. Globally ,the fast fashion industry creates 92 million tons of waste per year. Less than 15 percent of clothes are recycled or reused.

A style-conscious person expresses themselves through their clothes. These shoppers want second-hand clothes that show their personal style and values. They look for authentic and original pieces and avoid mainstream trends and fast fashion. They buy clothes that are timeless, well-made and all ow them to express their individual identity.

Going against the fast fashion trend, growing numbers of people are shopping for second-hand clothing. And the number of second-hand stores is also increasing. The research suggests much of this growth is due to shoppers considering themselves to be style-conscious.

We hope with increasing numbers of second-hand stores, markets and online platforms selling a range of quality, pre-loved clothes at different price points for different budgets—coupled with the growing acceptance of second-hand shopping—shoppers will consider buying second-hand more often. Not only are you helping the planet, you are also likely to be doing it with style.