When children start kindergarten, evident gaps in science knowledge already exist between Whites and minorities and between youngsters from upper-income and low-income families. And they often deepen into significant achievement gaps by the end of eighth grade if they are not dealt with during elementary school.

    The findings suggest that, in order for the United States to maintain(维持) long-term scientific and economic competitiveness in the world, policymakers need to renew efforts to ensure access(n.使用或见到的机会，权利) to high-quality, early learning experiences in childcare settings, preschools and elementary schools.

    The researchers' study tracked 7,757 children from their start in kindergarten to the end of eighth grade. Researchers found that, among kindergarteners with low levels of general knowledge, 62 percent were struggling in science by the time they reached third grade and 54 percent were struggling in that subject in eighth grade. And general knowledge gaps between minorities and Whites were already large at the time when students began kindergarten.

    “Children growing up in low-income families typically experience comparatively fewer early opportunities to learn about the natural and social sciences,” the authors wrote. “Their parents often have lower educational levels and therefore less science knowledge themselves as well as fewer resources available to direct the children's academic growth. Children raised in poverty often attend poorly resourced schools that futher limit their academic opportunities.”

    Morgan said that, within families, parents who regularly talk and interact with toddlers(学步的儿童) can point out and explain physical, natural and social events occurring around them daily. This might help youngsters learn facts and concepts that will prepare them to take better advantage of science instruction they receive during elementary and middle school.

    A qualified doctor who rarely practiced but instead devoted his life to writing．He once said: “Medicine is my lawful wife, and literature is my lover．” Russian writer Anton Pavlovich Chekhov, was a great playwright and one of the masters of the modern short story．

    When Chekhov entered the Moscow University Medical School in 1879, he started to publish hundreds of comic short stories to support his family．After he graduated, he wrote regularly for a local daily newspaper．

    As a writer he was extremely fast, often producing a short story in an hour or less．Chekhov's medical and science experience can be seen through the indifference (冷漠) many of his characters show to tragic events．In 1892, he became a full time writer and published some of his most memorable stories．

    Chekhov often wrote about the sufferings of life in small town Russia．Tragic events control his characters who are filled with feelings of hopelessness and despair．

    It is often said that nothing happens in Chekhov's stories and plays．He made up for this with his exciting technique for developing drama within his characters．Chekhov's work combined the calm attitude of a scientist and doctor with the sensitivity(敏感) of an artist．

    Some of Chekhov's works were translated into Chinese as early as the 1940s．One of his famous stories, The Man in a Shell, about a school teacher's extraordinarily orderly life, was selected as a text for Chinese senior students．

    It'll soon be the birthday of one of my closest friends, Susie. I still cannot decide what to give her. She's a rare friend because she has been there for me all the time whenever I need a friend to talk to. I can always depend on her to be the first to arrive to give me advice when I have problems. I guess I am so lucky to have her as a friend.

    It's more than seven years since I first met Susie in our school. I joined the theater group and she was a director then. At first I thought she was intimidating but in the end I realized that she needed to keep a strict image in order for her actors and actresses to take her seriously. And then during practice I got a chance to know her better. In fact, she was a friendly and warm-hearted person. Soon we become good friends.

    I don't know exactly what to give my friend on her birthday as I believe she has everything. So it's really hard to buy her a gift she will like. This year I want something different and special but I don't know what to give. One day I searched the internet without any purpose and to my surprise there is a really lovely site where you can buy all kinds of gifts.

    I scanned（浏览）some of their items and I found cool and exciting gifts. I chose a special personalized bracelet（手镯）. I'm sure that this will look perfect on her. I put our arms as part of the design of the bracelet so that it'll remind us that we'll forever be friends. I can't wait to give her my gift but I won't tell her yet. I don't want to destroy the surprise.

    Cheating can happen in a lot of different ways. When people cheat, it's not fair to other people, like the kids who studied for the test or who were the true winners of a game.

Many people like the action of cheating. It makes difficult things seem easy, like getting all the right answers on the test. But it doesn't solve the problem of not knowing the material and it won't help on the next test — unless the person cheats again.

    Some people lose respect for cheaters and think less of them. The cheaters themselves may feel bad because they know they are not really earning that good grade. And, if they get caught cheating, they will be in trouble at school, and maybe at home, too.

    Some kids cheat because they're busy or lazy and they want to get good grades without spending the time studying. Other kids might feel like they can't pass the test without cheating. Even when there seems to be a “good reason” for cheating, cheating isn't a good idea.

    If you were sick or upset about something the night before and couldn't study, it would be better to talk with the teacher about this. And if you don't have enough time to study for a test because of swim practice, you need to talk with your parents about how to balance swimming and school.

    A kid who thinks cheating is the only way to pass a test needs to talk with the teacher and his or her parents so they can find some solutions together. Talking about these problems and working them out will feel better than cheating.

    Native to America, the cane toad (癞蛤蟆) was introduced to Northern Queensland 70 years ago to control sugarcane beetles (甘蔗害虫). The toads failed in that duty but spread across Queensland and into neighboring northern areas.

    Now it calmly invades(侵略) the stats of Western Australia and New South Wales ( NSW). NSW wildlife experts fear the amphibians － which have poisonous backs that kill hungry predators (食肉动物) 一will have a terrible effect on native animals.

    Those fears may be about to be realized. Australia's leading government research body, the Commonwealth Science and Industry Research Organization (CSIRO), forecasts that a rise in average temperatures will make NSW an ideal living place for the cane toads.

    Tony Robinson, head of CSIRO's Wildlife, Pests, and Diseases Program, said climate change is increasing the amount of suitable living place for the cane toads.

    “With climate change, the cane toads might go down as far as Sydney and some areas of Western Australia,” Robinson said.

Recent estimates put the pace of the toads' westward march at nearly 17 miles (27 kilometers) a year and slightly slower from north to south.

    “More southerly (南部的) cities, such as Melbourne and Adelaide, would likely remain too cold and dry to ever suit the toads,” Robinson noted, “but Perth could expect cane toads in five years' time.”

    Sydney could see their arrival in the next 20 years.

    Robinson said there is no method that will keep the toads under control.

    The cane toads already cover at least half of Queensland and most of the northern country. The toads are believed to number in the billions.

    A Venezuelan virus was tried in the 1990s but had to be given up after it was found to also kill native frog species. Scientists and governmental bodies believe a national approach is needed.

    The main threat the toads cause to species such as dingoes, and crocodiles is the poison contained in glands (腺) on each of their shoulders. The poison sprays out when the toads are threatened or handled roughly. The poison is made up of 14 different chemicals.

    Cane toads also compete, and usually win, the hunt for food and living space.

    "”If the government and other states combine resources, I believe we can achieve a very practical biological-control research program,” Bums said.

    Inspired by a 9-year-old cyclist, Lauren Turner, who can only use one hand, a group of University of Guelph students has won an international award for their invention－a bike brake lever (刹车手柄) that pulls both the front brake and the back brake at the same time.

    Lauren Tuner was able to ride her bike, but not as confidently and quickly as her friends.

    “She couldn't use the front brake. She only used the back brake, but the front brake makes you stop twice as fast,” says Micha Wallace, who, with Katie Bell, Anina Sakaguchi and Andrew Morries won second prize in the James Dyson Award for their single-handed bike brake lever.

    "Lauren Turner tried the device (装置) first and she used it all last summer. She had no problems. It helped her go faster because she felt more confident in her braking abilities. She felt safer." says Wallace.

    The invention was the fourth-year design project for the four students. They designed, tested and created a prototype (模型) within a four-month period.

    When Wallace heard about the James Dyson Award on the news, she and her co-inventors entered their project in the U.K.-based contest, which rewards students designers who create products that improve the way we live. The students collected the runner-up prize－£2,000 for them and £500 for their school.

    As well, they had a chance to meet James Dyson, a U.K. famous inventor. Praising the students for their invention, Dyson says the single-handed brake lever could improve safety for all cyclists. By using both brakes at once, you could prevent the possibility of flying over the handlebars and ending up with an injury.

    The students hope to sell it to a major company. It may be used in other devices that require two hands for operation.