A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    Light travels at a speed which is about a million times faster than the speed of sound. In one second, light travels about 300,000 km, but sound travels only 344m. You can get some idea of this difference by watching the start of a race. If you stand some distance away from the Starter, you can see smoke come from his gun before the sound reaches your ears.
     This great speed of light produces some strange facts. Sunlight takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light rays (光线) left the moon 1.3 seconds before they reached you. The nearest star is so far away that the light which you can see from it tonight started to travel towards you four years ago at a speed of nearly 2 million km per minute. In some cases the light from one of tonight's stars started on its journey to you before you were born.

    Thus, if we want to be honest, we cannot say “The stars are shinning tonight.” We have to say, “The stars look pretty. They were shining four years ago but their light has only just reached Earth.”

    Music is an international language. The songs that are sung or played by instruments are beautiful to all people everywhere.

    Popular music in America is what every student likes. Students carry small radios with earphones and listen to music before class, after class and at lunch. Students with cars buy large speakers and play the music loudly as they drive on the street.

    Adult drivers listen to music on the car radio as they drive to work. They also listen to the news about sports, the weather, politics, and activities of the American people. But most of the radio broadcast is music.

    Pop or popular music singers make much money. They make a CD or tape which radio stations use in every state. Once the popular singer is heard throughout the country, young people buy his or her tapes. Some of the money from these tapes comes to the singer. Wherever the singer goes, all the young people want to meet him or her. Now the singer has become a national star.

    Besides pop music, there are two other kinds of music that is important to Americans. One is called folk music. It tells stories about the common life of Americans. The other is called western or country music. This was started by cowboys who would sing at night to the cows they were watching. Today, any music about country life and the love between a country boy and his girl is called western or country music.

    In Hollywood, as in war, truth is often the first casualty. Stories told on screen demand heroes, devils and a clear plot line. Real life, on the other hand, tends to get messy—the lines between good and bad often cross. Two years ago, director Oliver Stone was severely criticized in the press for playing fast and loose with certain facts in JFK. Jim Sheridan's In the Name of the Father has largely escaped such criticism in the U.S., but only because Americans are unfamiliar with the story it is based on.In Britain,where people have lived with the case of the Guildford Four for 20 years,the film's reception has been considerably stormier.

    The movie tells the tale of Gerry Conlon,who along with three other youths was falsely accused of killing five people in a 1974 I.R.A.bombing of two pubs in Guildford,England.The four—three men and a woman—served 14 years in prison before their convictions（定罪）were overturned. Seven friends and relatives of Conlon's (the Maguire Seven),including his father,also served many years on false charges of having made the bombs.

    Though Sheridan never set out to make a documentary,he has been attacked for needlessly twisting the facts of the case.The film,for instance,shows the Maguire Seven on trial with the Guildford Four,though the cases were tried separately.In some of its most affecting scenes,it shows Conlon,played by Daniel Day-Lewis,sharing a jail cell with his father,though the two were often not even in the same prison.A grand and heroic part is carved for actress Emma Thompson,playing Conlon's lawyer,Gareth Peirce,but in reality Peirce was a minor figure and another lawyer, Alastair Logan,deserves most of the credit for freeing the Four.An important scene in which Peirce steals a crucial piece of evidence from a police file was fabricated for the film;it was a police investigation that uncovered the buried evidence of Conlon's innocence.

    Sheridan insists that he was seeking an "emotional honesty" and that the real subject of his film was a son's changing relationship with his father.But if that was his intended subject,say some close to the case,the director should have used someone else's story."The truth is that Gerry Conlon had very little time for his father,"says Sean Smyth,an uncle."It's a good film,well acted and everything,"admits Conlon's aunt,Anne Maguire."But I think if they'd put more of the true facts in,it would have been a much more powerful film."

    A young woman carrying a three-year-old child got on a bus. The conductor hurried to give her a warm welcome and then kindly asked the other passengers to make more room for the woman and her kid. On seeing this, people were surprised and began to talk." You know this conductor used to be very rude. Now suddenly he has changed his bad behavior, "said a middle-aged man.

    "Yes, he should be praised and we must write a letter to the company," said a second passenger." That's right," another lady said, "I wish a newspaper reporter were here so that more people could learn from this conductor."

    Just then a gentleman who looked like a teacher turned to the conductor and said, "Excuse me, but can I know your name, please? Your excellent service must be praised…"

    Before he could open his mouth, the three-year-old kid sitting on the young woman's lap interrupted, "I know his name; I call him Dad."

    As the weekend approaches, perhaps you're looking forward to a meal out or sitting in front of the TV with a takeaway. But as you settle down to enjoy that comforting plate of beef or start spooning that fragrant lamb curry over the rice, will you be worrying about whether you are really eating what was written on the menu?

    Yesterday it was revealed by the Food Standards Agency that more than a fifth of the 665 meat samples tested last year contained DNA from animals not listed on the label. Of the 145 problem samples, 73 came from supermarkets, while 22 came from processing plants. The remaining 50 all came from restaurants.

    I have no doubt that over the next few years, the percentage of meal coming from dubious origins will continue to rise unless something drastic is done. Why? There are two main reasons. First, too many businesses are willing to boost their profits by adulterating their products in the meat industry. I believe there is a systemic problem within the meat industry that makes it particularly attractive to unscrupulous characters who are really nothing more than criminals，the second is the complexity and length of the meat supply chain. If you buy a chicken-based ready meal from a supermarket, as you might imagine, that chicken will pass through many hands before it ends up on your plate here. Worse still, the meat will often he partially processed somewhere along that chain—usually with salt and water added to boost flavour and volume—which is quite legal.

    Obviously, it is impossible for consumers to be detectives about every piece of meal they eat.

    However, what you can do is to avoid processed foods and never buy ready meals. Stay away from burgers made in factories. Don't go to chain restaurants. Instead, go to local, independent restaurants where it is more likely the chef and owner—often the same person—cares about where the meat comes from, and will be happy to tell you. So, try to buy your meat from a good local butcher.

    And no, what I am suggesting is not going to hurt your purse or wallet. The essence, then, is to buy meat that has had as small a journey from field to fork as possible, because that is the only way you can he sure of what you eat. It's that simple.