The streams are about 12 to 15 feet wide and 300 feet or more long, scientists said. "What we're dealing with is wet soil, thin layers of wet soil, not standing water," said Aifred  McEwen of the University of Arizona at Tueson! the principal scientist for the Mars Reconnaissance Orbiter's high-resolution imaging experiment,

     Because liquid water is essential to life, the findings could have major implications for the possibility of Martianlife, There searchers said further exploration is needed to determine whether microscopic life exists on the planet.

    The presence of liquid water could also make life easier for astronauts visiting or living on Mars. Watercould be used for drinking and for creating oxygen and rocket fuel. NASA's goal is to send humans there inthe 2030s.

    The evidence of flowing water consistslargely of dark, narrow streaks(条痕) on the surface that tend to appear and growd uring the warmest Martian months and fade the rest of the year.

    Mars is extremely cold even in summer,and the streaks are in places where the temperature is as low as minus 10 degrees Fahrenheit. But salt can lower the freezing point of water and melt ice.

    The source of the water is a mystery. Scientists noted it could be melting ice. It could be an underground a quifer, which is rock or sand that can hold water. It is possibly water vapor from the thin Martian atmosphere, Or it may be a combination Michael Meyer, lead scientistfor NASA's Mars exploration program, said the only definitive way for now to determine whether there's life on Mars is to collect rocks and soil foranalysis on Earth - something a U.S. lander set for lift-off in 2020 will do.

    Machu Picchu is an unusual site in Peru and one of the most mysterious wonders of the world. Built at almost 10,000 feet on the top of an Andean mountain, the Incas built hundreds of structures made of stone. A large number of Machu Picchu's surrounding structures date back to the early 13th century, but it was considered a chief sacred site far before then. The Inca people changed the large site into a very small but wonderful city, completely self-sufficient and hidden from below. Agricultural terraces (梯田) surrounded the entire city, fed by natural spring water, supporting the entire population.

Inca Trail

    The trail is one of the most famous in the world and regarded as one of the best. It covers only 26 miles, combining cloud forest, green mountain scenery, forest, and plenty of tunnels, paving stones, and ruins. The four-day hike begins slowly but quickly changes into a difficult journey suitable for those in excellent shape. The trail winds through the Andes, leading alongside and through ruins. Though independent hiking was once permitted, now it must be done with a guide.

Funerary Rock

    It is believed that the Funerary Rock at Machu Picchu was used as a place to prepare Inca nobles for preservation, or mummifying (做成木乃伊), a common habit among the tribe. Nobles would be laid out to be mummified by the hot sun and freezing cold nights after their organs were removed. The rock is also famous as a spot from which a view of the city is afforded.

Temple of the Sun

    Within the city's castle, deep within Machu Picchu, is the Temple of the Sun, accessed only by the Emperor and

    Inca priests. It means the Inca's advanced knowledge of religion, weather, and nature, showing the great extent

    Incas went to adapt to and learn about nature. Still unbroken, the temple was built to honor the god Inti, who is exactly the sun. The temple was effectively protected. It was also a very important scientific center, built in half-moon shape with openings facing north and east. The windows' shadows in the center of the temple helped see the start of winter solstice (至日), showing farming season.

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    A receptionist is required from 1st June 2017 at Dartford Science & Technology College. The position is only from 8:30 am to 4:30 pm Monday to Thursday and 8:30 am to 4:00 pm Friday, with an hour's break for lunch every day. The successful applicant must have a good telephone manner, good interpersonal skills and IT skills.

    Science Technician

    Term time plus 10 days, 37 hours per week

    We are looking for a technician to provide a technical support service for science teaching staff. Applications are to be received no later than midnight on 10th June 2015.

    Health & Social Care Teacher

    Our client, an 11-18 mixed comprehensive school in Ealing, West London, is currently seeking a teacher for Health & Social Care. The position will be a full-time post until July 2015. We require an energetic teacher to develop the learning potential of students. We are seeking someone with excellent subject knowledge who can combine academic strictness and achievement with enjoyment of teaching Health & Social Care.

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    It has long been thought that elephants rely on their large ears and bathing in rivers to stay cool in hot climates. New research, however, has showed that the world's largest land animals have a secret trick of controlling their body temperatures.

    Scientists have long been puzzled by temperature regulation(调节)in elephants. Generally, animals with large bodies tend to hold more heat because, compared to their size, they have a small surface area for heat to escape from. Elephants, with their heavy­weight frames, would appear to be at a disadvantage in the heat of their African and Asian habitats, especially because they have thick fur to protect them from bushes and trees.

    Scientists thought that these creatures, which weigh up to 13 tons when fully­grown, grow large ears to help them stay cool. The skin on the ears is thinner, so blood which flows into them cools down more easily. But findings by researchers at two universities in Vienna have showed that elephants are also able to cool down by increasing the blood flow to skin patches(斑) in other parts of their bodies.

    The researchers studied six African elephants at Vienna Zoo as they moved between outdoor and indoor environments to see how the temperature on their skin surface would change. They found up to 15 “hot spots” all over an elephant's body surface, in addition to large patches on the ears. The study shows how these patches expand as the air temperature increases and more blood flows nearer to the skin surface. Other experiments show that elephants in the wild use the same “windows” to control their body temperature.

    Elephants have two additional ways to stay cool: flapping(拍打)the ears and bathing. Together with these tricks, the skin hot spots allow the animals to keep their body temperature always at about 36 degrees—one degree less than humans'.

    A few years ago, bubble tea(奶茶) exploded as a popular drink for Internet foodies(吃货) everywhere. Many take this Taiwanese drink as a guilt-free snack similar to juice or a cup of coffee. After all, it has the word "tea" in it, so it has to be healthy…right?

    Not quite. Like coffee, bubble tea's ingredients(成分，配料) might not be so bad on their own, but when they're loaded with sweetener(甜味剂) and artificial flavor(人工香料), they lose their nutritional (营养的) value fast.

    It all starts with those "bubbles" found at the bottom of your drink, which are actually round pieces of tapioca(木薯淀粉). Called "tapioca pearls(珍珠)," they're actually made from a vegetable that grows in South America. And as it turns out, those little balls are loaded with sugar—and not the nutritious, fiber-rich(富含纤维) kinds found in whole grains(全麦类), either.

Cooking tapioca pearls only makes it worse. They're typically fried in hot water, along with even more added sugar, for up to three hours. By that point, these balls could have nearly 160 calories per ¼ cup.

    And don't even get us started on what comes in the extra syrups(糖浆). Thanks to all those processed(加工的) ingredients, the average bubble tea can easily reach 300 to 400 calories per cup!

    On top of being an unhealthy habit, bubble tea could even shorten your life. In 2012, a group of German researchers from the University Hospital Aachen reportedly found aspolychlorinated biphenyls, or PCBs, in tapioca ball samples. These cancer-causing chemicals have also been shown to have other bad effects on the immune(免疫), reproductive(生殖), and nervous systems.

    You might want to lay off your bubble tea addiction. Thankfully, we have a few choices for low-calorie, healthier drinks, instead.

    If you fancy a break over the festive season, then why not join Solos Holidays on one of their special Christmas or New Year breaks. These social events are a great opportunity to mix and associate.

    Stratford Christmas Market

    A wonderful way to start getting into the festive spirit on this 2-night Christmas market break. Wander under the twinkling lights while shopping for homemade gifts and tasting warming wine, roast chestnuts or luxury(奢侈的) chocolates. Explore historical Stratford-upon-Avon and enjoy dinner on both evenings where you can relax, join in the hotel's party night and hit the dance-floor with other single guests.

    Departure: 7th December

    Price: £380, Breakfast Dinner

    New Year in Brighton

    Head to the south coast and the busy town of Brighton for a 3-night break this New Year. Celebrations begin with a Solos welcome drink before joining other single guests for dinner and musical entertainment. The next morning we take the fun ‘Only in Brighton Tour' showcasing all things special about Brighton, before New Year's Eve kicks off with a Gala dinner and party to take us into 2019.

    Departure: 30th December

    Price: £555, Breakfast & Dinner

    To find out more about Solos Holidays Black Tie Balls, Party Nights, Dances & Festive Breaks that take place at venues(场所)across the UK throughout December: call 0844826 8515 or visit solosholidays.co.uk