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?

    For an increasing number of students at American universities, Old is suddenly in. The reason is obvious: the graying of America means jobs, coupled with the aging of the baby-boom generation, a longer life span means that the nation's elderly population is bound to expand significantly over the next 50 years. By 2050, 25 percent of all Americans will be older than 65, up from 14 percent in 1995.The change poses profound questions for government and society, of course. But it also creates career opportunities in medicine and health professions and in law and business as well. “In addition to the doctors, we're going to need more sociologists, biologists, urban planners and specialized lawyers,” says Professor Edward Schneider of the University of Southern California's (USC) School of Gerontology（老年学）.

    Lawyers can specialize in “elder law”, which covers everything from trusts and estates to nursing-home abuse and age discrimination. Businessmen see huge opportunities in the elder market because the baby boomers, 74 million strong, are likely to be the wealthiest group of retirees in human history. “Any student who combines an expert knowledge in gerontology with, say, an MBA or law degree will have a license to print money,” one professor says.

    Margarite Santos is a 21-year-old senior at USC. She began college as a biology major but found she was “really bored with bacteria.” So she took a class in gerontology and discovered that she liked it. She says, “I did volunteer work in retirement homes and it was very satisfying.”

    As we age, our ability to think and remember starts to deteriorate. But not everyone. Some of us have brains that age more slowly. Enter the super-ager!

    Super-agers are people over the age of 80 who have the brain structures and abilities of much younger people. Eighty-seven-year-old Bill Gurolnick is a super-ager. “What do I feel like? If I was to give a number, I probably feel like I'm about my early 70s…”

    Scientists know that parts of the brain decrease in size with age. But in super-agers that process is much slower. Emily Rogalski is a neuroscientist at Northwestern University's Feinberg School of Medicine, in Chicago, Illinois. In a recent study, she showed that super-agers have young brains. The area of the brain responsible for attention and memory—the cortex—was shown to be thicker in super-agers. “When we look at the cortex of their brain, we see that, on average, that it looks more like a 50-year-old brain that it looks like an average 80-year-old bran…”

    Not only do super-ages have thicker cortexes, they have more spindle neurons. These large brain cells appear to be involved with social-emotional communication. But their exact purpose is still a mystery. Scientists writing for Smithsonian magazine say they are “brain cells for socializing.”

    Several factors affect how our brains age. Scientists say super-agers have several things in common, including an active lifestyle. Many travel and play sports. They are often big readers. And they usually have healthy relationships and spend time with friends. Super-agers also seem to have certain common personality traits. Rogalski says they are, for the most part, known for their optimism, resilience and perseverance. Growing old, she adds, does not have to be depressing and sad. “Perhaps, if we expected a bit better from ourselves, then we would understand that not all aging is stressful!”

    Can we all be super-agers? The science behind super-aging is a relatively new, but growing field. Scientists involved in the research offer this advice as we age: Stay active. Learn new things. Challenge yourself. Surround yourself with healthy relationships.

    There are numerous amusement parks all over the world. A famous magazine, Amusement Today, does a survey among park lovers every year both in the US and overseas, based on which, “Top 5 List of the Best Amusement Parks in the World” has come out as follows:

    Disneyland, California

    Disneyland is a theme park in Anaheim, California, the US. More than 515 million guests have traveled to this American landmark from around the world since the park first opened to guests on July 17, 1955. The park consists of many world-famous sections, such as Main Street, Adventure Land, New Orleans Square, and so on.

    Magic Kingdom, Disney World, Florida

    Magic Kingdom is a theme park within the Walt Disney World Resort in Lake Buena Vista, Florida, near Orlando opened on October 1, 1971. It is the most famous theme park in Florida. The park's design and attractions don't make much difference from Disneyland Park in Anaheim.

    EPCOT, Disney World, Florida

    EPCOT is the second theme park built at the Walt Disney World Resort near Orlando, Florida. The park opened on October 1, 1982, and was named EPCOT Center from 1982 to 1993. It was the largest Disney theme park in the world until 1998, when Disney's Animal Kingdom opened.

    Disney-MGM Studios, Florida

    MGM's streets are the home for some great movie-themed attractions with a history of less than 30 years. With the addition of the Twilight Zone Tower of Terror and the Rock and

    Roller Coaster, the park is now home to Disney World's most thrilling rides.

    Universal Studios, Florida

    Go behind the scenes, beyond the screen and jump right into the action of your favorite movies at Universal Studios, the number one movie and TV theme park in the world.

    My husband and I wanted desperately the instant transformation from typical consumers to eco-conscious people. We switched our light bulbs to CFL(compact fluorescent light) bulbs to conserve energy. We went about the house turning off lights and unplugging appliances that weren't in use. But the rate of global warming exceeded our snail's pace conversion to greenhood. So I pressed onward.

    I decided to put veganism(素食主义) at the top of our agenda. Vegans refuse any animal flesh or commercial goods made from any animal byproducts such as milk or fats. All the family applauded this option except for my husband. Some kind of animal needed to sacrifice its dear life for his meal or it was his dinner. I cooked up a storm, struggling to prepare nutritious meals dominated by not-so-obvious vegan dishes like bean burritos and high-fiber vegetable stir-fry. It took a few days before he realized that he hadn't been eating any meat.

    "I feel like eating beef." he announced. So that night, I took full advantage of a zucchini (一种南瓜), cut it into chunky(粗大的) pieces and cooked them. Then I covered them with spices. My beef-starved husband had some and a curious look crossed his face.

    "Where's the beef?"

    "Living peacefully somewhere on an open plain where it belongs."

    "I knew it" he murmured. "You've surely made great contributions to the boom in cattle." His taste buds were developed completely around the flavor of every kind of animal: cattle, pigs, deer, lamb, chickens and ducks. Converting him was like feeding grass to a lion.

    I'm all for preserving our planet, but what good would it do to save the earth for tomorrow's generation if today's died of starvation? The next day, we went out for burgers. I was very careful to place the paper bag into our recycling bin.

    Scientists have found an unexpected use for virtual reality headsets (耳机). The devices (装置), widely used by computer gamers, show pictures that can be used to test the navigational (导航的) skills of people, who were thought to be at risk of dementia (痴呆). Those who do worse in the tests will be the ones more likely to develop Alzheimer's disease later in life, scientists now believe.

    The discovery that the loss of navigational skills was associated with Alzheimer's was made several years ago by Dennis Chan and his colleagues based at several centers in the UK. These studies used computers to test navigational tasks. But now scientists plan to take their tests to a new level with the use of the virtual reality headsets in which wearers are placed in man-made environments through which they must navigate.

    Around 300 people, aged between 40 and 60, will be arranged to participate in the study. Some will have a gene that puts them at risk of the condition or will come from a family with a history of Alzheimer's. Not all will certainly be affected by the disease, however. Chan's project aims to find out who will. Wearing the headsets, participants will be asked to navigate their way through a series of different environments and then remember the details.

    Researchers recently pointed out the significance of a tiny area of the brain known as the entorhinal cortex (an important memory center in the brain). It acts as a center in a widespread brain network that controls navigation. This now appears to be the first part of the brain that seems to be easily harmed by Alzheimer's.

    The goal of the work is to help people as they develop the disease. "So far, drug trials for Alzheimer's have been applied when people have already got dementia, by which time considerable damage to the brain has already occurred," Chan told the Obsenver. "If we can develop drugs and use them earlier, for example, before the disease has spread beyong the entorhinal cortex, then this would have the potential to prevent the dementia."