People aren't walking any more—if they can figure out a way to avoid it.

    I felt superior(不为……所动) about this matter until the other day I took my car to mail a small parcel. The journey is a matter of 281 steps. But I used the car. And I wasn't in any hurry, either. I had merely become one more victim of a national sickness: motorosis.

    It is an illness to which I had thought myself immune(免疫的), for I was brought up in the tradition of going to places on my own two legs. At that time, we regarded 25 miles as good day's walk and the ability to cover such a distance in ten hours as sign of strength and skill. It did not occur to us that walking was a hardship. And the effect was lasting. When I was 45 years old I raced -–and beat-—a teenage football player the 168 steps up the Stature of Liberty.

Such enterprises today are regarded by many middle-aged persons as bad for the heart. But a well-known British physician, Sir Adolphe Abrahams, pointed out recently that hearts and bodies need proper exercise. A person who avoids exercise is more likely to have illnesses than one who exercises regularly. And walking is an ideal form of exercise— the most familiar and natural of all.

    It was Henry Thoreau who showed mankind the richness of going on foot. The man walking can learn the trees, flower, insects, birds and animals, the significance of seasons, the very feel of himself as a living creature in a living world. He cannot learn in a car.

    The car is a convenient means of transport, but we have made it our way of life. Many people don't dare to approach nature any more; to them the world they were born to enjoy is all threat. To them security is a steel river thundering on a concrete road. And much of their thinking takes place while waiting for the traffic light to turn green.

    I say that the green of forests is the mind's best light. And none but the man on foot can evaluate what is basic and everlasting.

    Palema Malhotra and her husband Anil Malhotra have spent the last 25 years buying the waste agricultural land and reforesting it, to return the land to a bio – diverse rainforest for elephants, birds and other creatures.

    The couple owns 300 acres of land in Brahmagiri, India. They have spotted more than 300 kinds of birds as well as many rare and threatened animal species. But, this was not the scene in 1991 when Anil and Pamela came to this part of the country. “When I came here, it was a wasteland. The owner wanted to sell because he couldn't grow coffee or anything else,” says Anil who worked in the real estate（房地产）and restaurant business in the US before moving to India. “For me and Pamela, this was what we were looking for all our life.”

    The couple had a love for nature from their childhood. When the Malhotras came to India, the pollution horrified them. “That was when we decided to do something to reclaim（开垦）the forest in India,” says Anil. “We were not looking for money. Early on, we realized that shortage of fresh water will be a concern for India and the rest of the world. Acquisition, protection and reclamation of forested lands and wildlife habitat, where vital water sources have their origin, is the only way to save ourselves,” explains Anil.

    They sold what they owned in America, bought the first 55 acres and began to grow a forest. Soon they bought the land nearby as well. “Many of the farmers considered their holdings 'wasteland' as very little grew on it and were happy to get money,” says Anil.

    Hunting and poaching（偷猎）was a challenge and often the locals did not understand what this couple was doing, so it required a lot of talking to create awareness. They worked with the forest department to set up camera traps and keep poachers away. “There are times I have fought with poachers,” says Pamela.

    The BeiDou Navigation Satellite System（BDS）is a Chinese satellite navigation system. It consists of two separate satellite constellations（星座）. The first BeiDou system, officially called the BeiDou Satellite Navigation Experimental System and also known as BeiDou-1, consists of three satellites, which since 2000 has offered limited coverage and navigation services, mainly for users in China and neighboring regions. Beidou-1 was decommissioned at the end of 2012.

    The second generation of the system, known as COMPASS or BeiDou-2, became operational in China in December 2011 with a partial constellation of 10 satellites in orbit. Since December 2012, it has been offering services to customers in the Asia-Pacific region.

    In 2015, China started the build-up of the third generation BeiDou system（BeiDou-3）in the global coverage constellation. The first BDS-3 satellite was launched on 30 March 2015. Up to January 2018, nine BeiDou-3 satellites have been launched. BeiDou-3 will eventually consist of 35 satellites and is expected to provide global services upon completion in 2020. So far, China has sent 27 BeiDou satellites into space. When fully completed, BeiDou, the world's fourth navigation satellite system, following GPS in the United States, GLONASS in Russia and Galileo in the European Union, will provide an alternative global navigation satellite system to the United States owned Global Positioning System（GPS）, and is expected to be more accurate than the GPS. It was claimed in 2016 that BeiDou-3 will reach millimeter-level accuracy（with post-processing）, which is ten times more accurate than the finest level of GPS.

    According to China Daily, in 2015, fifteen years after the satellite system was launched, it was generating a turnover of $31.5 billion annually for major companies such as China Aerospace Science and Industry Corp, AutoNavi Holdings Ltd, and China North Industries Group Corp.

    Literature is an important part of a total language arts program at all grade levels because of the many benefits it offers.

    Literature provides pleasure to listeners and readers. It is a relaxing escape from daily problems, and it fills leisure moments. Making time for recreational reading and using high-quality literature help to develop enthusiastic readers and improve achievement. Developing a love of literature as a recreational activity is possibly the most important outcome of a literature program.

    Literature builds experience. Through reading, children expand their horizons through vicarious(引起共鸣的)experiences. They visit new places, gain new experiences, and meet new people. They learn about the past as well as the present and learn about a variety of cultures, including their own. They discover the common goals and similar emotions found in people of all times and places. Nory Ryan's Song by Patricia Reilly, Giff, a hard survival story, is set in Ireland during the potato hunger of I845,and Patricia Polacco's The Butterfly, deals with Nazis, resistance, and Jewish persecution(迫害)during World War II.

    Literature provides a language model for those who hear and read it. Good literature exposes children to correct sentence patterns, standard story structures, and varied word usage. Children for whom English is a second language can improve their English with the interesting context, and all children benefit from new vocabulary that is woven into the stories.

    Literature develops thinking skills. Discussions of literature bring out reasoning related to sequence; cause and effect; character motivation; predictions; visualization of actions, characters, and settings; critical analysis of the story; and creative responses.

    Literature helps children deal with their problems. By finding out about the problems of others through books, children receive insights into dealing with their own problems, a process called bibliotherapy. Children might identify with Gilly, living angrily in a foster home in Katherine Paterson's The Great Gilly Hopkins, or with Mary Alice, a city girl forced to live with her grandma in a "hick town" in Richard Peck's A Year Down Yonder.

    FROM dogs and cats to pandas and penguins, lists of adorable animals can be very varied. However, when it comes to scary animals, the answers are often more or less the same­snakes and spiders are among the most dreadful ones for the majority of us.

    However, most of us have never been bitten by a snake or a spider. So does this mean we are born with a fear of certain things?

    Scientists have been actively looking into it for a long time. For example, studies have suggested that babies find live animals much more interesting than stuffed （毛绒填充的） ones. This interest continues even if those animals are snakes and spiders.

    A study published in Psychological Science in 2008seemed to show that snakes did have a different impact on babies. When scientists presented babies with animal videos along with random sounds of happy or frightened human voices, hey found that babies looked at snakes for longer than any other animal however the voices sounded.

    Now, a team from Rutgers University in New Jersey, US has tried to challenge the idea that babies are born with a fear of snakes and spiders. According to the BBC, the researchers measured babies' physiological （生理的） responses as they watched videos of snakes and elephants paired with both fearful and happy voices.

    Scientists then set out to surprise the babies to see how they would react. They presented them with an unexpected bright flash of light as they watched a video. As the BBC explained, a surprise like this would be more intense （强烈的） if the babies were already scared, just like when we watch scary films and jump more if we are already scared.

    However, according to their findings, published recently in the Journal of Experimental Child Psychology, babies 'surprised responses were not bigger when watching a video of a snake, even when it was shown with a fearful voice. Their heart response was also lower, which also made it seem that babies were not scared.

    "Children do not have an innate fear of snakes," concluded the study. Even if previous studies had suggested that babies have different responses to snakes, it isn't necessarily related to fear. "It's possible that paying more attention to something might make fear learning easier later on. It leads to fear learning," said research co­author Vanessa LoBue. She further explained that it was a good thing that humans didn't have an inborn fear of snakes because it would make a young infant's desire to explore new things less strong.

    Instead, we have evolved to quickly learn to be afraid of something if it turns out to be dangerous.

    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.