Off the coast of Hawaii's Big Island swim masses of colorful tropical fish. Some of these fish will be caught and sold, ending up in aquariums around the world. Is the industry putting populations of the fish at risk?

    Scientists who have studied the Big Island fishery say it is well managed. Rules put in place more than 15 years ago have helped to protect the fish. Along 35% of the coastline, for example, fish collecting is banned. Two years ago, the state cut the number of fish species for the aquarium trade from hundreds to just 40.

    Conservationist Robert Wintner objects to the findings. Wintner, who owns snorkel shops across Hawaii, started the Snorkel Bob Foundation to protect the island's coral reefs(珊瑚礁). He says he simply doesn't see yellow tang(刺尾鱼)in the protected areas. “There should be millions of them,” he says. “Where are they?”

    Wintner says people believe the numbers in reports. But few people have actually dived into the coral reefs to see for themselves how many fish can be found there. According to Wintner, the coral reefs along the coast should be filled with yellow tang, but they are “virtually empty”. Empty reefs are not good for tourism, Wintner points out, which brings out $800 million yearly. By contrast, the aquarium-fish trade brings out just $2 million yearly.

    Experiments under way in several labs aim to create beneficial types of genetically modified foods, including starchier potatoes and caffeine-free coffee beans. Genetic engineers are even trying to transfer genes from a cold-winter fish to make a frost-resistant tomato.

    A low-sugar GM strawberry now in the works might one day allow people with health problems such as diabetes (糖尿病) to enjoy the little delicious red fruits again. GM beans and grains rich in protein(蛋白质) might help people at risk of developing kwashiorkor. Kwashiorkor, a disease caused by severe lack of protein, is common in parts of the world where there are severe food shortages.

    Commenting on GM foods, Jonathon Jones, a British researcher, said: "The future benefits will be enormous（巨大的）, and the best is yet to come". To some people, GM foods are no different from unmodified foods. "A tomato is a tomato," said Brian Sansoni, an American food manufacturer.

    Critics of GM foods challenge Sansoni's opinion. They worry about the harm that GM crops might do to people, other animals, and plants.

    In a recent lab study conducted at Cornell University, scientists tested pollen(花粉) made by BT corn, which makes up one-fourth of the U.S. corn crop. The scientist dropped the pollen onto milkweed, a plant that is the only known food source of a butterfly caterpillar(毛虫). Within four days of feeding on the leaves, almost half of a test group of caterpillars died. "This is a warning bell." said Cornell researcher Linda Raynor.

    Some insects that are not killed by GM foods might find themselves made stronger. How so? The insecticides are used on the crops to kill the pests. But GM plants produce a continuous level of insecticide. Insects relying on those crops may develop resistance to the plants and they may also develop a resistance to the insecticide.

    At the forum on GM food held last year in Canada. GM crops that have been made resistant to the herbicide might crossbreed with wild plants, creating "superweeds" that could take over whole fields.

    So where do you stand? Should GM food be banned in the United States, as they are in parts of Europe? Or do their benefits outweigh（胜过） any of the risks they might carry?

    You've just come home, after living abroad for a few years. Since you've been away, has this country changed for the better—or for the worse?

    If you've just arrived back in the UK after a fortnight's holiday, small changes have probably surprised you—anything from a local greengrocer suddenly being replaced by a mobile-phone shop to someone in your street moving house.

    So how have things changed to people coming back to Britain after seven, ten or even 15 years living abroad? What changes in society can they see that the rest of us have hardly noticed—or now take for granted? To find out, we asked some people who recently returned.

    Debi: When we left, Cheltenham, my home town, was a town of white, middle-class families—all very conservative (保守的). The town is now home to many eastern Europeans and lots of Australians, who come here mainly to work in hotels and tourism. There are even several shops only for foreigners.

    Having been an immigrant (移民) myself, I admire people who go overseas to find a job. Maybe if I lived in an inner city where unemployment was high, I'd think differently, but I believe foreign settlers have improved this country because they're more open-minded and often work harder than the natives.

    Christine: As we flew home over Britain, both of us remarked how green everything looked. But the differences between the place we'd left behind and the one we returned to were brought sharply into focus as soon as we landed.

    To see policemen with guns in the airport for the first time was frightening—in Cyprus, they're very relaxed—and I got pulled over by customs officers just for taking a woolen sweater with some metal-made buttons out of my case in the arrivals hall. Everyone seemed to be on guard. Even the airport car-hire firm wanted a credit card rather than cash because they said their vehicles had been used by bank robbers.

    But anyway, this is still a green, beautiful country. I just wish more people would appreciate what they've got.

    My dad loved pennies, especially those with the elegant stalk of wheat curving around each side of the ONE CENT on the back. Those were the pennies he grew up with during the Depression (大萧条).

    As a kid, I would go for walks with Dad, spying coins along the way—a penny here, a dime (一角硬币) there. Whenever I picked up a penny, he'd ask, "Is it a wheat?" It always thrilled him when we found one of those special coins produced between 1909 and 1958, the year of my birth.

    One gray Sunday morning in winter, not long after my father's death in 2002, I was walking down Fifth Avenue, feeling bereft. I found myself in front of the church where Dad once worked. I was warmly shown in and led to a seat. Hearing Dad's favorite "A Mighty Fortress Is Our God", I burst into tears. We'd sung that at his funeral. After the service, I shook the pastor's hand and stepped onto the sidewalk—and there was a penny. I bent to pick it up, turned it over, and sure enough, it was a wheat. A 1944, a year my father was serving on a ship in the South Pacific.

    That started it. Suddenly wheat pennies began turning up on the sidewalks of New York everywhere. I got most of the important years: his birth year, my mom's birth year, the year he graduated from college, the year he met my mom, the year they got married, the year my sister was born. But alas, no 1958 wheat penny—my year, the last year they were made.

    The next Sunday, after the service, I was walking up Fifth Avenue and spotted a penny in the middle of a crossing. Oh, no, it was a busy street; cabs were speeding by—should I risk it? I just had to get it.

    A wheat! But the penny was worn, and I couldn't read the date. On arriving home, I took out my glasses and took it to the light. There was my birthday!

    I found 21 wheat pennies on the streets of Manhattan in the year after my father died, and I don't think that's a coincidence.

    Once I was troubled by tourists to do a favor for them—take their photos. Sometimes they complained that the photos I took were not good.

    Now fellow travelers trouble me in a different way—with their selfie sticks (自拍杆). I fear my head will be knocked or my eyes poked (戳) by the poles with mobile phone cameras put on them.

    Admittedly, it is a good invention. With a cool $3, you can take solo or group photos without asking for a favor from strangers. But if you want to take your selfie sticks out to travel to the West, think twice. Selfie-sticks bans have been spreading in some of the world's important museums, galleries, parks and soccer stadiums including Disney. Visitors have to leave their selfie sticks in a locker before entering to protect paintings, individual privacy and the overall visitor experience.

    In China, selfie sticks are still widely used. People would do anything to take a perfect selfie and don't pay attention to their surroundings and other travelers. Many examples have shown things could go horribly wrong when people were taking selfies. For example, earlier this year, a starfish died at the Shanghai Science and Technology Museum after a visitor took it out to take a selfie, and last year a criminal was caught by the Chinese police after the criminal posted a selfie of himself on Wudang Mountain and shared it on social media, according to the Xinhua News Agency.

    Thus, I strongly advise travelers not to take a selfie in a crowded public place, indoors or at any sensitive places such as cemeteries and memorial places, especially when the police are looking for you. If you are a die-hard selfie fan, there are some options cooler than a selfie stick. One is a waterproof (防水的) wrist-band called a “pop stick”. Just like the slap bracelets (手镯) we used to wear when we were kids, it unrolls into a stiff selfie stick. Another one is “selfie ring”, an accessory that helps you stick your phone to your hand so you can snap better selfies.

    February has long been a month of romance. With the sweet smell of roses in the air, romantic films hit cinemas and love stories fill newspapers and magazines.

    On the 14th day, it is customary for a boy to take his girlfriend out to dinner, buy her flowers and chocolates, write poems, sing to her or even spell out her name with rose petals!

    This is the scene that greets you on Valentine's Day, named after Valentine who was a priest in third century Rome. When the emperor decided that single men made better soldiers than those with wives, he banned marriage.

    But Valentine continued to perform marriage ceremonies for young lovers in secret. When his actions were discovered, the emperor had him put to death.

    While in prison, it is said that Valentine fell in love with the daughter of his prison guard. Before his death, he wrote her a letter, which he signed "From your Valentine", an expression that is still in use today.

    Valentine died for what he believed in and so was made a Saint, as well as becoming one of history's most romantic figures.

    Nowadays, Valentine's Day wins the same popularity among Chinese young people. It is a time when students "don't want to be alone" according to Gao Shunjie, a student reporter for 21st Century Teens in Jinling High School, Nanjing. Some of her classmates are planning to make Valentine's cards for parents, teachers and friends. Others want to hold parties at which they will exchange small gifts and eat heart shaped cakes. The idea is to have fun and encourage people to share in the spirit of St Valentine.