In colonies (群体) that range in size from a few hundred to tens of millions, they organize their lives with a clear division of labor. Even more amazing is how they achievethis level of organization. Where we use sound and sight to communicate, ants dependprimarily on pheromone (外激素), chemicals sent out by individuals and smelled or tastedby fellow members of their colony. When an ant finds food, it produces a pheromone that will lead others straight to where the food is. When an individual ant comes under attack or is dying, it sends out an alarm pheromone to warn the colony to prepare for a conflict as a defense unit.

         In fact, when it comes to the art of war, ants have no equal. They are completely fearless and will readily take on a creature much larger than themselves, attacking in large groups and overcoming their target. Such is their devotion to the common good of the colony that not only soldier ants but also worker ants will sacrifice their lives to help defeat an enemy.

         Behaving in this selfless and devoted manner, these little creatures have survived on Earth, for more than 140 million years, far longer than dinosaurs. Because they think as one, they have a collective (集体的) intelligence greater than you would expect from itsindividual parts.

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.

    Dictionaries are not closed books. There is still plenty of room for more words in these great vocabulary authorities.

    Dictionaries are not closed books. There is still plenty of room for more words in these great vocabulary authorities. New words are continually being created and added to our language. And many of today's word experts can credit a famous mathematician with the creation of the method by which they develop many new words. The mathematician was an Englishman named Charles L. Dodgson. In addition to working with figures, Dodgson wrote books. His imaginative stories and poems have made Dodgson beloved to generations of readers. We know him, however, not by the name of Dodgson but by his pen name, Lewis Carroll.

    Lewis Carroll has delighted countless readers, young and old, with Alice in Wonderland, Through the Looking Glass, and numerous poems. In these works, Carroll developed dozens of nonsensical words such as "chortle" and "galumph". Many of these words are combined naturally with more common words in the English language. Carroll referred to his made-up words as "portmanteau" words, named after a kind of leather suitcase that opens into two compartments. The name was well suited, because most of Carroll's words had two compartments. Rather than being entirely fabricated（虚构）, they were usually made from the combined parts of two different words. A "snark", for example, clearly came from a snake and a shark.

    Although Carroll died long ago, his technique continues to be used today. We clearly see his influence in such words as smog, brunch, and guesstimate.

    Some people will do just about anything to save money. And I am one of them. Take my family's last vacation. It was my six-year-old son's winter break from school, and we were heading home from Fort Lauderdale after a week long trip. The flight was overbooked, and Delta, the airline, offered us $400 per person in credits to give up our seats and leave the next day. I had meetings in New York. So I had to get back. But that didn't mean my husband and my son couldn't stay. I took my nine-month-old and took off for home.

    The next day, my husband and son were offered more credits to take an even later flight. Yes, I encouraged—okay, ordered—them to wait at the airport, to “earn” more Delta Dollars. Our total take: $1,600. Not bad, huh?

    Now some people may think I'm a bad mother and not such a great wife either. But as a big-time bargain hunter, I know the value of a dollar. And these days, a good deal is something few of us can afford to pass up.

    I've made a living looking for the best deals and exposing (揭露) the worst tricks. I have been the consumer reporter of NBC's Today show for over a decade. I have written a couple of books including one titled Tricks of the Trade: A Consumer Survival Guide. And I really do what I believe in.

    I tell you this because there is no shame in getting your money's worth, I'm also tightfisted when it comes to shoes, clothes for my children, and expensive restaurants. But I wouldn't hesitate to spend on a good haircut. It keeps its shape longer, and it's the first thing people notice. And I will also spend on a classic piece of furniture. Quality lasts.

    THREE years ago Jenny Salgado, a Dominican shop assistant, moved to Highland town, a neighborhood of Baltimore. When she arrived the shop she works in, it was one of only a few Spanish businesses. Now there are many more. "It's good now if you speak Spanish," she smiles.

    Baltimore has been losing people for 60 years. To address this, its mayor, Stephanie Rawlings-Blake, wants to make it the most immigrant-friendly city in the world. Its libraries provide Spanish-language exercise classes. To help those with no papers, the city is introducing micro-loans (小额贷款) which require no credit checks; city police would no longer routinely check the immigration status of citizens or enforce any federal immigration law unless required to. The then governor, Martin O'Malley made it possible for illegal immigrants to get driving licenses.

    Such welcoming policies are spreading. Such cities as Cleveland, Dayton and Philadelphia all eagerly try to please immigrants. Rick Snyder, the governor of Michigan, has asked the federal government to offer 50,000 visas to people who agree to live in Detroit. His administration has made it easier for skilled migrants to get professional licenses.

    When a city's population falls, both tax receipts and services fall. Half-deserted neighborhoods breed (滋生) crime, driving yet more people to leave. No city has escaped this death circle without attracting new residents, says Steve Tobocman of Global Detroit.

    Several studies suggest that when immigrants arrive, crime goes down, schools improve and shops open up. In Detroit, immigrants living near the tiny separate city of Hamtramck have formed local watches to guard against thieves. Their neighborhoods are not just safer; they are also among the only places where it is as easy to buy fresh vegetables as drugs and alcohol.

    But attracting new immigrants to the cities which most need them is hard, argues Audrey Singer of the Brookings Institution. They care about the same things as everyone else: safe streets, good schools and jobs. Cities which have lost population for decades struggle with all of these.