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.

    Obama, Lady Gaga and Steve Jobs—what do they have in common? They are, of course, all Americans. And according to a survey by social networking site baidu. com, they all best illustrate(举例说明) the word “cool”.

    But just what does it mean to say someone is “cool”? Most would answer that it is something to do with being independent-minded and not following the crowd.

    Yale University art professor Robert Farris Thompson says that the term “cool” goes back to 15th century West African philosophy. “Cool” relates to ideas of grace under pressure.

    “In Africa, ” he writes, “coolness is a positive quality which combines calmness, silence, and life.”

    The modern idea of “cool” developed largely in the US in the period after World War II. “Post-war ‘cool' was in part an expression of war-weariness (厌战情绪), ... it went against the strict social rules of the time,” write sociologists Dick Pountain and David Robins in Cool Rules: Anatomy of an Attitude.

    But it was the American actor James Dean who became the symbol for “cool” in the hugely successful 1955 movie Rebel without a Cause. Dean plays a tough guy who disobeys his parents and the authorities. He always gets the girl, smokes cigarettes, wears a leather jacket and beats up bullies. In the movie, Dean showed what “cool” would mean to American young people for the next 60 years.

    Today the focus of “cool” has changed to athletics (体育运动) stars. Often in movies about schools, students gain popularity on the athletics field more than in the classroom. This can be seen quite clearly in movies like Varsity Blues and John Tucker Must Die.

    But many teenagers also think being smart is cool. Chess and other thinking games have been becoming more popular in schools.

    “Call it the Harry Potterization of America—a time when being smart is the new cool,” writes journalist Joe Sunnen.

    In US, the potato is one of the most widely consumed crops. French fries are commonly found in typical American fast-food burger joints and cafeterias. French fries were introduced to the US when Thomas Jefferson served them in the White House during his presidency from 1801 to 1809. Potato chips are popular with consumers as well.

    The humble potato is more than just a kind of food. In many ways it's part of the American pop culture. Let's take a look at some pop culture potatoes.

Mashed Potato dance

    The Mashed Potato dance is a craze that began in 1962. The name of the dance came from the song it accompanies, Mashed Potato Time, performed by American R&B singer Dee Dee Sharp. The move vaguely resembles that of the Twist dance style, by Sharp's fellow Philadelphian.

Chubby Checker.

Hot Potato!

    Hot Potato! is an action puzzle video game released in 2001. In the game the player must drive a bus and clear the road of alien potato beings. The potato beings are either red or blue; when two like-colored potatoes touch each other, they disappear. Over the years, Hot Potato! has received mostly positive reception from critics.

Mr. Potato Head

    Mr. Potato Head is an American toy invented by George Lerner in 1949. The toy consists of a plastic potato model and a variety of plastic parts like hands, feet, ears and mouths. In 1952, Mr. Potato Head became the first toy advertised on television. This commercial revolutionized marketing and caused a boom that solidified this toy's place in American pop culture.

    My mother is a hard-working and kind woman. She is very busy from morning till night. As a teacher, she works hard.{#blank#}1{#/blank#} Both my brother and I love her dearly as she loves us.

    My mother has been teaching math at a middle school in my hometown. She goes to work early in the morning and does not return home until late in the afternoon.{#blank#}2{#/blank#} She treats them with patience and teaches them well. For her excellent quality and very good teaching results, she has been elected as a model teacher several times.

    {#blank#}3{#/blank#} Every day, when she comes back home from work, she sets about doing housework, sweeping the living room and bedrooms or cleaning the furniture, and putting everything in good order. She seems to be busy all the time. As she has been very busy working every day, she looks older than her age. But she looks as cheerful and happy as ever. Mother never buys expensive dresses for herself, but she often buys some inexpensive but high quality clothes for us.{#blank#}4{#/blank#} She just eats a plain meal outside when she is too busy to cook herself. She lives a busy yet simple life, without any complaints.

    Often she says to us, “work while you work, and play while you play. That is the way to be happy and gay. If you do not work, you will become lazy and be of no use to society”. What a piece of good advice this is! {#blank#}5{#/blank#} This advice of hers will always serve as a guide to my behavior. My mother is great indeed, and I always feel proud of her.

A. She enjoys listening to classic music.

B. As a mother, she takes good care of us and gives us every comfort.

C. She loves her students and cares for them.

D. She never goes to expensive restaurants to enjoy meals.

E. My mother is hard-working and never wastes money.

F. I never forget it and always bear it in my mind.

G. Can you tell us something about your mother?

    You might think that “global warming” means nothing more than a rise in the world's temperature. But rising sea levels caused by it have resulted in the first evacuation (撤离) of an island nation, the citizens of Tuvalu will have to leave their homeland.

    During the 20th century, sea level rose 8~12 inches. As a result, Tuvalu has experienced lowland flooding of salt water that has polluted the country's drinking water.

    Paani Laupepa, a Tuvaluan government official, reported to the Earth Policy Institute that the nation suffered an unusually high number of fierce storms in the past ten years. Many scientists connect higher surface water temperatures resulting from global warming to greater and more damaging storms.

    Laupepa expressed dissatisfaction with the United States for refusing to sign the Kyoto Protocol, an international agreement calling for industrialized nations to reduce their greenhouse gas emissions (排放), which are a main cause of global warming. “By refusing to sign the agreement, the US has effectively taken away the freedom of future generations of Tuvaluans to live where their forefathers have lived for thousands of years.” Laupepa told the BBC.

    Tuvalu has asked Australia and New Zealand to allow the gradual move of its people to both countries.

    Tuvalu is not the only country that is vulnerable (易受影响的) to rising sea levels. Maumoon Gayoon, president of the Maldives, told the United Nations that global warming has made his country of 311,000 an “endangered nation”.

    Many Americans think of driverless cars as a futuristic technology that will revolutionize travel in cities and along state highways. But recent experiments are proving that autonomous vehicles also have the potential to improve the quality of life for millions of Americans underserved by traditional modes of transportation, such as the elderly and disabled, so long as lawmakers make smart policies that pave the way for innovation.

    A retirement community in San Jose, Calif. , which has been transformed by a small fleet of driverless taxis, shows the potential of self-driving cars to transform people's lives. Built by a tech start-up called Voyage, the modified Ford Fusions are currently limited to a two-mile road, but residents are already having the benefits of these autonomous vehicles, which allow them to participate in social activities they would otherwise be unable to enjoy simply because they could not get to them.

    When the trial run finally expands to 15 miles of road, these residents—whose average age is 76—will also have a convenient and reliable new way to appointments. As these cars continue to serve residents there, it is easy to understand why California is moving to simplify regulations for the industry.

    In Michigan, forward-thinking policies have the potential to unlock other hidden benefits of autonomous vehicles, especially for those with physical disabilities. The Michigan Disability Rights Coalition has strongly advocated for the development of this technology, saying that it could give people with disabilities greater opportunities in the workforce and enable them to lead more fulfilling, independent lives.

    Many recognize that autonomous vehicles will be the future of transportation, but it is too often overlooked that this future cannot arrive fast enough for millions of Americans who are forced to depend on others for day-to-day travel. The policymakers should follow the lead of places like California and Michigan, and pass rules and regulations to unlock these hidden benefits of driverless cars.