Disposing(处理) of waste has been a problem since humans started producing it. As more and more people choose to live close together in cities, the waste-disposal problem becomes increasingly difficult.

    During the eighteenth century, it was usual for several neighboring towns to get together to select a faraway spot as a dumpsite. Residents or trash haulers(垃圾托运者) would transport household rubbish, rotted wood, and old possessions to the site. Periodically(定期的) some of the trash was burned and the rest was buried. The unpleasant sights and smells caused no problem because nobody lived close by.

    Factories, mills, and other industrial sites also had waste to be disposed of. Those located on rivers often just dumped the unwanted remains into the water. Others built huge burners with chimneys to deal with the problem.

    Several facts make these choices unacceptable to modern society. The first problem is space. Dumps, which are now called landfills, are most needed in heavily populated areas. Such areas rarely have empty land suitable for this purpose. Property is either too expensive or too close to residential(住宅区的)neighborhoods. Long-distance trash hauling has been a common practice, but once farm areas are refusing to accept rubbish from elsewhere, cheap land within trucking distance of major city areas is almost nonexistent.

    Awareness of pollution dangers has resulted in more strict rules of waste disposal. Pollution of rivers, ground water, land and air is a price people can no longer pay to get rid of waste. The amount of waste, however, continues to grow.

    Recycling efforts have become commonplace, and many towns require their people to take part. Even the most efficient recycling programs, however, can hope to deal with only about 50 percent of a city's reusable waste.

Choose Your One-Day-Tours!

    Tour A - Bath &Stonehenge: including entrance fees to the ancient Roman bathrooms and Stonehenge -￡37 until 26 March and ￡39 thereafter.

    Visit the city with over 2,000 years of history and Bath Abbey, the Royal Crescent and the Costume Museum, Stonehenge is one of the world's most famous prehistoric monuments dating back over 5,000 years.

    Tour B - Oxford & Stratford  including entrance fees to the University St Mary's Church Tower and Anne Hathaway's -￡32 until 12 March and ￡36 thereafter.

    Oxford: Includes a guided tour of England's oldest university city and colleges. Look over the "city of dreaming spires(尖顶）"from St Mary's Church Tower. Stratford: Includes a guided tour exploring much of the Shakespeare wonder.

    Tour C - Windsor Castle &Hampton Court including entrance fees to Hampton Court Palace -￡34 until 11 March and ￡37 thereafter.

    Includes a guided tour of Windsor and Hampton Court, Henry VIII's favorite palace. Free time to visit Windsor Castle (entrance fees not included).With 500 years of history, Hampton Court was once the home of four Kings and one Queen. Now this former royal palace is open to the public as a major tourist attraction. Visit the palace and its various historic gardens, which include the famous maze (迷宫)where it is easy to get lost!

    Tour D -Cambridge including entrance fees to the Tower of Saint Mary the Great -￡33 until 18 March and ￡37 thereafter.

Includes a guided tour of Cambridge, the famous university town, and the gardens of the 18th century.

    Christopher Thomas, 27, was a writer by night and a teacher by day when he noticed he was always tired and was losing weight fast. Diagnosed with diabetes (糖尿病), Thomas would need to inject himself with insulin (胰岛素) three times a day for the rest of his life or risk nerve damage, blindness, and even death. And if that weren't bad enough, he had no health insurance.

    After a month of feeling upset, Thomas decided he'd better find a way to fight back. He left Canton, Michigan for New York, got a job waiting tables, nicknamed himself the Diabetic Rockstar, and created diabeticrockstar.com, a free online community for diabetics and their loved ones—a place where over 1,100 people share personal stories, information, and resources.

    Jason Swencki's son, Kody, was diagnosed with type diabetes at six. Father and son visit the online children's forums (论坛) together most evenings. “Kody gets so excited, writing to kids from all over,” says Swencki, one of the site's volunteers. “They know what he's going through, so he doesn't feel alone.”

    Kody is anything but alone: Diabetes is now the seventh leading cause of death in the United States, with 24 million diagnosed cases. And more people are being diagnosed at younger ages.

    These days, Thomas's main focus is his charity (慈善机构), Fight It, which provides medicines and supplies to people—225 to date—who can't afford a diabetic's huge expen­ses. Fight－it.org has raised about $23,000—in products and in cash. In May, Thomas will hold the first annual Diabetic Rockstar Festival in the Caribbean.

    Even with a staff of 22 volunteers, Thomas often devotes up to 50 hours a week to his cause, while still doing his full­time job waiting tables. “Of the diabetes charities out there, most are putting money into finding a cure，” says Bentley Gubar, one of Rockstar's original members. “But Christopher is the only person I know saying people need help now.”

    Starting Cycling

    We have two services designed to give people the confidence and knowledge to cycle successfully.

    Lessons

    All our instructors have been trained to National Standards level of “Bikeability”. This means you will be trained to a standard consistent across the whole country.

    There are 3 levels of skills to progress through. Children would start with levels 1 & 2, progressing from the playground or park to cycle on less busy local roads. Teenager and adult beginners can also learn levels 1 & 2 in an off-road and quiet environment.

    Confident teenagers and adults can broaden their skills by learning level 3, using multi-lane (多道) roads and larger roundabouts (环岛). We provide both a complete package of lessons for the beginner or individual lessons tailored to the client. You can ride a bike but don't feel confident about right turns on multi-lane roads. Whatever the need we can address and practice until perfect!

    Everyone can be taught to ride a bike!

    We train both adults and children.

    We cover London Zones 1 & 2

    The cost is ￡30 per hour.

    Guided Ride

    We know that riding on the roads in London can be scary, and if you have to navigate (确定行车路线) as well it can become a real hard task! The Guided Ride service takes all the stress out of it for you by providing the following:

    Route planned in advance to suit your skill level. Route map provided to you.

    Cycle and equipment checked. We will teach you a simple method to check basic roadworthiness (车辆性能) of your bike that you can perform on a weekly basis.

    Route discussed and focus given to any areas requiring special attention.

    Cycle along with the instructor close behind. Here the traffic can be controlled by the instructor and rider observed.

    Occasionally stopping to discuss events.

    We currently cover London Zones 1 & 2. Please contact us if your requirements are outside of these areas.

    Cost ￡30

    Many non-edible (不能吃的), poisonous or otherwise not pleasant-tasting butterflies have distinct colors and pat terns. As a result, other more palatable (可口的)butterflies have evolved to mimic (模仿)those patterns to avoid being consumed by predators. There are several types of mimicry in butterflies: Bayesian mimicry, Müllerian mimicry, wasp (黄蜂)mimicry and tiger complex mimicry. Birds will con­sume unpalatable butterflies and associate their colors and patterns with the negative experience, thus avoiding the but­terflies performing mimicry. It is possible that birds even communicate their experience with other birds.

    Bayesian mimicry was established by the naturalist Hen­ry Walter Bates in 1862. He first observed that mimicry involved a palatable butterfly resembling an unpalatable, often toxic (有毒的)，butterfly. This mimicry will only work when the toxic model species outnumbers the non-toxic spe­cies. He believed that mimicry was the result of edible but­terflies producing mutations (突变)making them resemble their inedible cousins. This in turn resulted in the increased survival of the butterflies containing the mutation and resul­ted in the similarities between species. In 1879 another naturalist, Johann Friedrich Theodor Müller, observed that in some cases of mimicry both the mimic and the model are un­palatable. He considered this to be a cooperative mimicry and believed the species evolved side by side in a mutually benefi­cial relationship. If a bird tried to eat a member of either spe­cies, it would then avoid both. Wasp mimicry is similar to Bayesian mimicry, but instead of mimicking another unpalata­ble butterfly species, the mimic resembles a wasp to avoid predators.

    The tiger complex is a group of around 200 species of Neotropical butterflies that are involved in the most well-known form of mimicry. It is named such because the patterns of all of the included species are black on a background of either orange or yellow, resembling a tiger. In the com­plex are many unpalatable species, a few toxic species and a large number of completely edible species. Members of the tiger complex are all known for congregating (集合)in large groups that would normally be easy food for birds. Fortunately, birds have no interest in them due to their mimicry.

    Science Advances published a new research report, saying bees are capable of addition and subtraction (减法)in Arithmetic(算术) learning—using colors in the place of plus and minus symbols.

    It isn't unusual to see the ability to count—or at least distinguish between differing quantities in the animal kingdom—Such ability has been seen in frogs, spiders, and even fish. But solving equations (方程式) using symbols is rare, so far only achieved by famously brainy animals such as chimpanzees. The previous research says the social insects, ants, can count to four and understand the concept of zero and researchers wanted to test the limits of what their tiny brains can do.

    The experiment goes like this. Scientists trained 14 bees to link the colors blue and yellow to addition and subtraction, respectively. They put the bees at the entrance of a Y-shaped maze (迷宫), where they were shown several shapes in either yellow or blue. If the shapes were blue, bees got a reward if they went to the end of the maze with one more blue shape (the other end had one less blue shape); if the shapes were yellow, they got a reward if they went to the end of the maze with one less yellow shape.

    The testing worked the same way: Bees that "subtracted" one shape when they saw yellow, or "added" one shape when they saw blue were considered to have aced the test. The bees got the right answer 63% to 72% of the time, depending on the type of equation and the direction of the right answer—much better than random guesses would allow.

    While the results came from just 14 bees, researchers say the advance is exciting. If a brain about 20,000 times smaller than ours can perform maths using symbols, it could pave the way to novel methods in artificial intelligence (AI) and machine learning. Just don't ask the bees to do your homework anytime soon.