You may have seen a talking parrot on a TV show, in a movie, or even in someone's home. The parrot has learned to copy sounds that people make. Birds are not the only animals that can copy the noises they hear. Dolphins, bats, and some apes also copy sounds. Now we can add elephants to this list of copycats.

    Dr. Joyce Poole is a zoologist. She studies the sounds of elephants. While she was in Kenya, she would hear strange noises made by Mlaika after sunset. Mlaika was a 10-year-old African elephant.

    Mlaika lived near a highway. Dr. Poole says, “I could not tell the difference between Mlaika's call and the distant truck noise.” She and other scientists studied Mlaika's sounds. It turned out that Mlaika was copying the sounds of the trucks driving by. Why would Mlaika copy trucks that she heard going by on the highway? Animals that are able to copy sounds may enjoy practicing new sounds. When they are kept outside of their natural environment, they may copy unusual sounds. That may be why an elephant would copy the sound of a truck.

    “Mlaika was not the only copycat elephant,” Dr. Poole says. Calimero is a 23-year-old male African elephant. He spent 18 years with two female Asian elephants. Asian elephants make chirping sounds (sounds made by birds) to talk with one another. African elephants usually do not make chirping sounds. But Calimero now does. He is copying his Asian elephant friends. Dr. Poole says that elephants need to form bonds with their family and friends. She says, “They make sounds to communicate with each other. When they are separated, they use sounds to keep in contact.”

    Parrots, dolphins, humans, and elephants show that being a copycat is one way that animals and people make new friends and keep old ones.

    When was the last time you relied on an old-fashioned map to figure out the route to an unfamiliar place? For many, the GPS has revolutionized navigation, making a paper map almost obsolete? So how has this piece of technology developed over its 26 years of existence? On February 14,1989,the first satellite in the US Global Positioning System was sent into space from Cape Canaveral, beginning the start of one of the wonders of the modern world.

    GPS stands for Global Positioning System, which is made of a network of around 30 satellites that move around the earth. The system uses a process called trilateration to find out one's position. By measuring the time it takes for the signal to reach one satellite, the GPS can determine your distance from the satellite, creating a sphere(范围) of possible locations. Measuring your distance from at least three satellites will narrow your location to the place where the three spheres cross one another, to the accuracy(精确) of about less than 1 meter!

    The GPS was first invented during the Cold War by the United States Department of Defense. In 1960, the first system, which was made of just five satellites, was put into place. It was initially created for strictly military(军事的) use; however, in 1983, as a result of faulty navigation technology, a Korean passenger plane mistakenly flew into USSR territory(苏联领土) and was shot down. In order to prevent such bad events, American President Ronald Reagan allowed civilian(民用的) use of the GPS.

    Over the next ten years, the system's accuracy improved as the network was increased to 24 satellites. And during the first Persian Gulf War, the new GPS was finally used by the military. Now scientists use the technology to track animals to better understand their movement and behavior. Parents who may be worried about their children can also use GPS technology to track them.

Your 2018 Reading List, Provided by Bill Gates

    Most of us can't live like billionaire Microsoft co-founder Bill Gates, but we can read like him. Gates recommended four books in 2018—though some were published earlier.

    Leonardo da Vinci, by Walter Isaacson (2017)

    The bestselling biographer of Steve Jobs and Albert Einstein researched deeply into da Vinci's contributions beyond art, highlighting the breadth of his scientific, technological, and creative output. “Leonardo nearly understood almost all of what was known on the planet at the time. That's mostly because of his curiosity about every area of natural science and the human experience,” said Gates.

    The Best We Could Do: An Illustrated Memoir, by Thi Bui (2017)

    Gates calls this graphic novel “really impressive”. Bui is the daughter of Vietnamese refugees who came to America after the fall of Saigon, and becoming a parent inspired her to look into her own parents' miserable history. “I was struck by how the experiences Bui illustrates manage to be both universal and specific to their circumstances,” said Gates.

    Lincoln in the Bardo, by George Saunders (2018)

    Saunders, a long-time short story writer, won high praise for this novel. The book imagines the ghosts that haunt (萦绕) the basement of Willie Lincoln, Abraham Lincoln's son, who died at 11 in real life. “Willie's death after the Civil War made the president have a new understanding of the grief he's creating in other families by sending their sons off to die in battle,” said Gates.

Origin Story: A Big History of Everything, by David Christian (2018)

    This new book is by the creator of Big History, a free, online social studies course. It traces history in wide, sweeping movements, starting with the Big Bang, and it provides, in effect, a short course in modern science. This is a brief history of the universe. “David gets a little stuck on the current economic and political problems in the West, and I wish he talked more about the role innovation will play in preventing the worst effects of climate change,” said Gates.

    Often people use laptops(手提电脑) on trains and airplanes, in airports and hotels. These laptops connect people to their workplace. In the United States today, laptops also connect students to their classrooms.

    Westlake College in Virginia will start a laptop computer program that allows students to do schoolwork anywhere they want. Within five years, each of the 1500 students at the college will receive a laptop. The laptops are part of a $10 million computer program at Westlake, a 110-year-old college. The students with laptops will also have access to the Internet. Besides, they will be able to use e-mail to "speak" with their teachers, their classmates and their families. However, the most important part of the laptop program is that students will be able to use computers without going to computer labs. They can work with it at home, in a fast-food restaurant or under the trees—anywhere at all!

    Because of the many changes in computer technology, laptop use in higher education, such as colleges and universities, is workable. As laptops become more powerful, they become more similar to desktop computers. Also, the portable(便携式的)computers can connect students to not only the Internet, but also libraries and other resources. State higher-education officials are also testing laptop programs at other universities, too.

Gene technology to benefit people

    Among all the fast growing science and technology, the research of human genes, or biological engineering as people call it, is drawing more and more attention now. Sometimes it is a hot topic discussed by people.

    The greatest thing that gene technology can do is to cure serious diseases that doctors at present can almost do nothing with, such as cancer and heart disease. Every year, millions of people are murdered by these two killers. And to date, doctors have not found an effective way to cure them. But if the gene technology is applied, not only these two diseases can be cured completely, bringing happiness and more living days to the patients, but also the great amount of money people spend on curing their diseases can be saved, therefore it benefits the economy as well. In addition, human life span(寿命) can be prolonged.

    Gene technology can help people to give birth to more healthy and clever children. Some families, with the English imperial(皇室) family being a good example, have hereditary(遗传的) diseases. This means their children will for sure have the family disease, which is a great trouble for these families. In the past, doctors could do nothing about hereditary diseases. But gene technology can solve this problem perfectly. The scientist just need to find the wrong gene and correct it and a healthy child will be born.

    Some people are worrying that the gene research can be used to manufacture human beings in large quantities. In the past few years, scientists have succeeded in cloning a sheep; therefore these people predict that human babies would soon be cloned. But I believe cloned babies will not come out in large quantities, for most couples in the world can have babies in very normal way. Of course, the governments must take care to control gene technology.

No matter where I direct my gaze, the landscape is dotted with the skeletal frames of new structures taking shape. The familiar neighborhoods of my youth, once adorned with the charm of time-honored edifices, have largely vanished, replaced by the sleek silhouettes of contemporary high-rises. There is a rationale for this transformation: residents are in pursuit of the amenities that modern living promises.

However, the question that lingers is, how can the younger generation grasp and uphold their cultural heritage if the tangible remnants of it are continually erased? The advocacy for the conservation of historical buildings transcends mere sentimental yearning for the past. Economic considerations also lend strong support to the cause of preservation.

The restoration and safeguarding of historical districts can serve as a catalyst for economic growth, enticing tourists and small enterprises to the locality. A case in point is the historic Al Bastikiya neighborhood in Dubai, which annually attracts a multitude of visitors from across the globe. It also draws the interest of local inhabitants who are keen on exploring the history of their city.

Critics often contend that preserving historical monuments is an expensive endeavor, but numerous recent initiatives have shown this belief to be unfounded. In fact, the process of refurbishing an existing structure for alternative use can be approximately £40 per square meter less costly than even the most elementary new construction, all the while retaining the architectural elegance of the original structure. Moreover, despite the common assertion that older buildings are less energy efficient and thus have a larger environmental footprint, architects and environmental specialists assert that the most eco-friendly building is the one that already exists. New construction typically has a more detrimental environmental impact, as it necessitates the procurement and transportation of brand-new materials over potentially lengthy distances, rather than utilizing recycled materials that are readily available on site.

In essence, we recycle many other items in our daily lives, and the same principle should be applied to buildings. The act of preserving historical structures presents a multitude of opportunities; in stark contrast, demolition is an irreversible act. Once these architectural gems are lost, they are gone forever, severing an integral thread in our cultural tapestry that can never be regenerated. The decision to preserve or demolish is thus not merely one of aesthetics or economy, but also one of heritage and legacy.