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 has risen 8～12 inches. As a result, Tuvalu has experienced lowland flooding of salt water which 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 green house 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”.

    Ali, the boxing legend, died on Friday night at 74，after a Long battle with Parkinson's disease.

    Cassius Clay (Ali) was just 12 years old in 1954 when he got ready to beat the boy who stole his bicycle in his hometown of Louisville, Ky. But a local policeman warned him that he'd need to learn to box first. At just 89 pounds, Clay had his first fight and his first win just weeks later, according to Bleacher Report. By 1964, he was the heavyweight champion of the world, alter upsetting Sonny Liston.

    In 1969, he was forbidden to do boxing over his refusal to join the army and go to Vietnam. Ali was reportedly drowning in debt and still appealing his conviction(上诉).He made pocket change by touring colleges to discuss the war, and, as Playbill points out, he starred in the Broadway musical, Buck White.

Ali sang nearly every song in the musical, playing a black lecturer addressing a meeting organized by a black political group. But he would never return to the stage after his conviction was cancelled.

    In November 1990, Ali met with Iraq president Saddam Hussein in Baghdad on a "good-will tour" in an attempt to negotiate the release of 15 Americans held hostage(人质)in and Kuwait.  Ali was criticized by then-President George H. W, Bush and The New York Times, both of whom expressed concerns that he was fueling propaganda (宣传) machine.

    Despite running out of medicine for his disease and waiting more than a week to talk to Hus-rein, Ali was able to bring all 15 of a group of American war prisoners home.

    While Jennifer was at home taking an online exam for her business law class, a monitor a few hundred miles away was watching her every move.

    Using a web camera equipped in Jennifer's Los Angeles apartment, the monitor in Phoenix tracked how frequently her eyes moved from the computer screen and listened for the secret sounds of a possible helper in the room. Her Internet access was locked－remotely－to prevent Internet searches, and her typing style was analyzed to make sure she was who she said she was: Did she enter her student number at the same speed as she had in the past? Or was she slowing down?

    In the battle against cheating，this is the cutting_edge and a key to encourage honesty in the booming field of online education. The technology gives trust to the entire system，to the institution and to online education in general. Only with solid measures against cheating, experts say, can Internet universities show that their exams and diplomas are valid—that students haven't just searched the Internet to get the right answers.

    Although online classes have existed for more than a decade, the concern over cheating has become sharper in the last year with the growth of “open online courses.” Private colleges, public universities and corporations are jumping into the online education field. Spending millions of dollars to attract potential students, while also taking steps to help guarantee honesty at a distance.

    Aside from the web cameras, a number of other high-tech methods are becoming increasingly popular. Among them are programs that check students' identities using personal information, such as the telephone numbers they once used.

    Other programs can produce unique exams by drawing on a large list of questions and can recognize possible cheaters by analyzing whether difficult test questions are answered at the same speed as easy ones. As in many university classes, term papers are scanned against some large Internet data banks for cheating.

    The United States of America is faced with serious traffic problems. Too many cars travel on the freeways to and from the city. This heavy traffic causes delays and lots of pollution from cars that are using their engines but not moving anywhere. Many cars going nowhere is called a "traffic jam".

    While many cities in the United States have traffic problems, some of the worst are in Los Angeles, California, which is a big city with a large downtown area. One of the reasons why there is so much traffic is that few people use public transportation to get around.

    Experts say one possible solution to the traffic problems in Los Angeles would be to make people want to use the public transportation system of buses instead of their own cars. People say the buses should be made easier, faster, less costly and more dependable than driving a car.

    One suggestion is to reduce the cost of taking the bus. Also, Los Angeles could make the buses easier for people to use. The buses could travel to more places in the city. And there could be more special lanes on the freeways that only buses could drive in. These changes would make taking the bus faster and easier than driving a car.

    Other experts have said that the best way to ease traffic problems is to charge people money to drive on the freeways. These charges, or tolls, would be for the most crowded roads. The tolls would be in effect during the times of a day when most people drive to work and home. These times in the morning and late afternoon are called "rush hour". People would try to avoid driving on these roads, which would decrease the amount of traffic. Also, the money collected from these tolls could be used to improve the roads and public transportation system.

    In 1953, a mountain climber reported seeing a bar-headed goose soar over the peak of Mount Everest (珠穆朗玛). It was thought impossible. Now researchers who raised 19 of the geese—named for the black stripes on the backs of their heads—have shown the birds really fly so high.

    The team trained the youngsters to fly in a large wind tunnel wearing backpacks and face masks full of sensors that recorded their heart rate. blood oxygen levels, temperature, and metabolic rate—how many calories they burned per hour. The researchers simulated(模拟)10w-, medium-, and high-altitude conditions by altering the concentration of oxygen supplied to face masks worn by each goose as it flew in the tunnel.

    Birds already have a better heart and lungs than mammals for sustained physical activity. And researchers knew that bar-headed geese have even larger, thinner lungs that let them breathe more deeply and an even bigger heart to pump more oxygen to muscles than other birds.

    The wind tunnel experiments showed that when the concentration of oxygen was at its lowest-like the 7% found on top of Mount Everest versus 21% at sea level—the geese's heart rate and frequency of wing beats remained the same even as their metabolic rate dropped. Somehow, the birds managed to cool down their blood-the measured blood temperature dropped so it could take in more oxygen, the researchers report today in eLife. This cooling likely helps compensate for the very thin air, the team says.

    Although well trained, the birds were only willing to stay in the air a few minutes-or less when wearing their backpacks and flying at 6ihigh" altitudes. So it's not clear whether these adaptations alone are what make it possible to fly the 8 hours it takes to climb over Mount Everest. But those few minutes showed these geese really could fly over the top of Mount Everest.

It was not until photographer Rita Nannini left New York that she grew fascinated by the city's subways. While living in Manhattan for some 15 years in the 1980s and early 1990s, Nannini only commuted (通勤) on the one train-given the subway system's bad reputation. But after relocating to New Jersey for several years where subway is not an option, Nannini found that absence did make the heart grow fonder — maybe even for pizza rats. During her visit back to New York, Nannini nodded, noticing improvements in the subway's facilities.

While Nannini was waiting for a train, a bench on the platform opposite caught her attention due to the ever changing faces and characters. They were people of different accents, colors and beliefs. They were from all walks of life, a diverse mix of New Yorkers all there for their own different reasons. Having learned the teenagers' popular "End of the Line" challenge — boarding trains at random and riding them until their final destination; Nannini decided to visit every first and last stop across the NY subway's lines with her beloved camera.

Nannini's "End of the Line" experience saw her traveling some 665 miles across 26 routes in New York city. She took over 8,000 photos of the final stations, as well as the communities they served. In many cases, she rode the routes two or three times over to ensure she got "the shot". "The project really shows me how important the subway is, and how sustainable it makes our lives," she said 

"It's often said that my photos show the end of the lines — the last stops," she said. "But theend of the line is indeed the start for so many people. That made me think about who the people and the communities that live at the two ends are and what it is that the subway means to them."

Nannini was proud of her set of images directly challenging the traditions of story telling, which echoed both the boredom and excitement of travel on tracks.

Nannini enjoyed taking her time, starting her challenge in 2013 and only shooting the final photos last year. Her first monograph on the terminal stops of the NY subway was released in April 2023.

"When you drive in the suburbs, you don't have those encounters," she continued. "People enter your life on the subway. That's what strikes me most on my jouney on tracks."