How could we possibly think that keeping animals in cages in unnatural environments, mostly for entertainment purposes, is fair and respectful?

    Zoo officials say they are concerned about animals. However, most zoos remain “collections” of interesting “things” rather than protective habitats. Zoos teach people that it is acceptable to keep animals bored, lonely, and far from their natural homes.

    Zoos claim to educate people and save endangered species, but visitors leave zoos without having learned anything meaningful about the animals' natural behavior, intelligence, or beauty. Zoos keep animals in small spaces or cages, and most signs only mention the species' name, diet, and natural range. The animals' normal behavior is seldom noticed because zoos don't usually take care of the animals' natural needs.

    The animals are kept together in small spaces, with no privacy and little opportunity for mental and physical exercise. This results in unusually and self-destructive behavior called zoo-chosis(圈禁性精神病). A worldwide study of zoos found that zoochosis is common among animals kept in small spaces or cages. Another study showed that elephants spend 22 percent of their time making repeated head movements or biting cage bars, and bears spend 30 percent of their time walking back and forth, a sign of unhappiness and pain.

    Furthermore, most animals in zoos are not endangered. Captive breeding(圈养繁殖) of endangered big cats, Asian elephants, and other species has not resulted in their being sent back to the wild. Zoos talk a lot about their captive breeding programs because they do not want people to worry about a species dying out. In fact, baby animals also attract a lot of paying customers. Haven't we seen enough competitions to name baby animals?

    Actually, we will save endangered species only if we save their habitats and put an end to the reasons people kill them. Instead of supporting zoos, we should support groups that work to protect animals' natural habitats.

    Anyone watching the autumn sky knows that migrating birds fly in a V formation, but scientists have long debated why. A new study finds that these big－winged birds carefully position their wingtips and flap(拍动) at the same rate, probably to catch the upward movement of air and save energy during flight.

    There are two reasons birds might fly in a V formation: It may make flight easier, or they're simply following the leader. Squadrons(中 队) of planes can save fuel by flying in a V formation, and many scientists suspect that migrating birds do the same. Models that treated flapping birds like fixed－wing airplanes show that they probably save energy by drafting off each other, but currents created by airplanes are far more stable than those coming off of birds.

    Just as aerodynamic(气动力) calculations would predict, the birds positioned themselves to fly just behind and to the side of the bird in front, timing their wing flaps to catch the uplifting eddies(涡流). When a bird flew directly behind another, the timing of the flapping reversed(相反) so that it could minimize the effects of the downdraft coming off the back of the bird's body. “We didn't think this was possible,” Usherwood says, considering that the difficult achievement requires careful flight and incredible awareness of one's neighbors. “Perhaps these big V formation birds can be thought of quite like an airplane with wings that go up and down.”

    The findings likely apply to other long－winged birds, such as pelicans and geese, Usherwood says. Smaller birds create more complex wakes(尾波) that would make drafting too difficult. The researchers did not attempt to calculate the birds' energy savings because the necessary physiological measurements would be too invasive for an endangered species. Previous studies show that birds can use 20% to 30% less energy while flying in a V.

    Scientists do not know how the birds find that aerodynamic sweet spot, but they suspect that the animals line themselves up either by sight or by sensing air currents through their feathers. In future studies, the researchers will switch to more common birds, such as pigeons or geese. They plan to investigate how the animals decide who sets the course and the pace, and whether a mistake made by the leader can ripple through the rest of the flock to cause traffic jams.

    NOT all memories are sweet. Some people spend all their lives trying to forget bad experiences. Violence and traffic accidents can leave people with terrible physical and emotional scars. Often they relive these experiences in nightmares.

    Now American researchers think they are close to developing a pill, which will help people forget bad memories. The pill is designed to be taken immediately after a frightening experience. They hope it might reduce ,or possibly erase(抹去),the effect of painful memories.

    In November, experts tested a drug on people in the US and France. The drug stops the body releasing chemicals that fix memories in the brain. So far the research has suggested that only the emotional effects of memories may be reduced, not that the memories are erased.

    The research has caused a great deal of argument. Some think it is a bad idea, while others support it.

    Supporters say it could lead to pills that prevent or treat soldiers' troubling memories after war. They say that there are many people who suffer from terrible memories.

    "Some memories can ruin people's lives. They come back to you when you don't want to have them in a daydream or nightmare. They usually come with very painful emotions," said Roger Pitman, a professor of psychiatry at Harvard Medical School. "This could relieve a lot of that suffering."

    But those who are against the research say that changing memories is very dangerous because memories give us our identity (特质). They also help us all avoid the mistakes of the past.

    "All of us can think of bad events in our lives that were horrible at the time but make us who we are. I'm not sure we want to wipe those memories out, "said Rebecca Dresser, a medical ethicist.

    Scientists recently discovered three tyrannosaur (霸王龙) trackways in Canada. The trackways suggest the meat eaters traveled and hunted in groups. The 70-million-year- old footprints are the first tyrannosaur trackways ever found.

    Tyrannosaurs were a type of meat-eating dinosaur that included the strong Tyrannosaurus rex and Albertosaurus. “Groups of tyrannosaurs may have stuck together as a group to increase their chances of bringing down animals and individually surviving,” study coauthor Richard McCrea says. He works for Canada's Peace Region Paleontology Research Centre. It's believed that tyrannosaurs were solitary creatures. The newly discovered trackways could change the way scientists look at these frightening beasts.

    Trackways can uncover a lot about the social behavior of a species. Unfortunately, very few tyrannosaur footprints have ever been found, and until recently, the only ones known were single prints discovered in Mongolia, the western U.S., and western Canada. But in October 2011, a hunting guide named Aaron Fredlund found two tyrannosaur track marks near Tumbler Ridge, an area in the foothills of the Canadian Rockies. Over the next year, McCrea and his team searched the site and found the remaining trackways.

    The footprints are at about the same depth, which suggests the tyrannosaurs moved through the area at the same time. Impressions of the dinosaurs' rough skin are even visible in the prints. The prints are also in near-perfect condition. That's because the ground had a high clay (黏土 ) content when the dinosaurs walked through the area. The land was later covered by a thick layer of volcanic ash, which kept the marks intact (完整). "This is the most ideal situation you could ask for," McCrea says.

    Researchers aren't sure of the exact species of tyrannosaur that left the prints. But the historic findings show a great deal about how the beasts moved and behaved. “We have extremely convincing evidence that tyrannosaurs traveled in groups,” says McCrea. "This is probably the most important evidence to come out to date on that topic."

    Winning literary competitions doesn't always lead to fame. But having a few such wins to boast about does you no harm when approaching editors or agents, so if you have dreams of a writing career, these could be the place to begin. Below is a list of the most interesting competitions. Bear in mind that contests with smaller prizes attract fewer entries and are therefore easier to win.

    Wundor Editions Poetry Competition

    Wundor Editions are looking for creative writers to enter their latest poetry contest. If you happen to be 16 or over, send in a poem on any subject running to as many words as you think you can get away with before the judge's eyes glaze over (兴趣丧失).

    Closing: Nov.30. Prize: £ 500. Entry Fee: £ 10.

    Manning's Pit Poetry Competition

    It doesn't sound very attractive but it seems Manning's Pit is something of a beauty spot with more than its share of wildlife. But it's now under threat. This contest aims of raise funds to help save it. Your task is to write a poem of up to 40 lines about Manning's Pit or a similar treasured and threatened piece of countryside near a town or village.

    Closing: Nov.30. Prizes: £ 100, £ 30, £ 20. Entry Fe: £ 3.

    Commonwealth (英联邦) Short Story Competition

    This contest from Commonwealth Writers is for unpublished short fiction of between 2,000 and 5,000 words aimed at adults. But you have to be a citizen of a Commonwealth country. You can write your story in English, Bengali, Chinese, Portuguese, Samoan, Tamil, Kiswahili or Malay.

    Closing: No.1. Prize: £ 5,000. Entry Fee: £ 25.

    Southword Fiction Chapbook Competition

    To enter this international contest from the Munster Literature Centre in Cork, Ireland you should submit 10,000 to 15,000 words of fiction in the form of a collection of short stories. Stories can have been published previously in web or print journals, but not in a stand-alone publication by the author.

    Closing: Oct.31. Prizes: Best International Entry and Best Irish Entry. Entry Fee: £ 5 for one, £ 10 for six.

    Many seniors feel pressured to go straight from high school to college, but Camden Olson, who graduated from the Latin School of Chicago in the US last year, didn't give in. She decided to spend a gap year-taking a year off before college-raising a guide dog for Guiding Eyes for the Blind in Maine. The non - profit provides trained guide dogs to blind and visually - impaired (视力障碍的) people. "This is something I've always wanted to do." Olson said.

    It is becoming more and more popular among American teenagers to have a gap year. Some students use the year off to figure out what they want to do: travel the world or save money for college.

    Olson is using her time to follow a passion she's had since 7th grade. For years, she kept an eye on guide dog services until she came across the opportunity at Guiding Eyes. With support from her friends, family and teachers, Olson went for it. Olson's volunteer work centers around Derby, a one-year-old black dog.

    "My job is to raise him to be well-mannered and socialized," she said. "Guide dogs can't be distracted. They go everywhere with their visually-impaired owner. They give a blind person a lot of support, too."

    Of course, there's an end in sight for Derby and Olson's close bond. When Derby celebrates his own graduation, Olson will have to say goodbye to him.

    "No doubt there will be tears, but, if he passes, I will be so happy for him to become a working dog," she said.

    While some do not agree that gap years are a good choice, Olson said she's seen major success. In fact, she'll be attending Princeton University soon and is thinking about majoring in biology.

    "I think I'm already so much more mature than I was," she said. "So many kids come back from gap years a lot more focused and prepared."