It happens every spring. Flowers come out everywhere on the same day. But how do plants “know” when to flower?

For years, it has been a difficult question for scientists. But a US research group may have finally answered it—the secret lies in a protein(蛋白质)called FKF1. This helps plants to know when the days become long and when they get short. Then they can tell the seasons are changing.

    Researchers found the FKF1 protein when they were studying a plant called Arabidopsis(拟南芥). It is sensitive(敏感的)to sunlight, and can be made active by sunlight.

    Plants produce this protein every day in the late afternoon all year. If there is no light at this time, for example in winter when the sun goes down early, the protein won't be active. But when spring comes and the days get longer, the FKF1 protein can be made active by day light and the plants “know”it is time to flower. “If there is light in the late afternoon, plants will know that the days are getting longer and that it is the best time for flowers to come out,”explained Takato Imaizumi, leader of study. But when conditions are poor for growing, such as during autumn or winter when the weather is cold and days are short, plants won't flower.

    Although researchers have only studied how the FKF1 protein works in the Arabidopsis, they believe that it is the same with many other plants, including crops such as rice and wheat. This could be useful to the agricultural industry.

    "If we can control when flowers come out, we might be able to increase crop production,”Imaizumi said.

    A hobby can be almost anything that a person likes to do in his free time. Hobbyists raise pets, watch birds, paint pictures, play the piano and grow flowers. They also go to concerts, climb mountains, go fishing, skate and swim. They collect everything from books to butterflies and from boxes to stamps.

    People follow hobbies because these activities offer enjoyment, friendship，knowledge and relaxation. Sometimes they even make money by following a hobby. Hobbies help people relax after hard work, and provide a balance between work and play. Hobbies also offer interesting activities for persons who are retired. Anyone, rich or poor, old or young, can follow an interesting hobby.

Hobbies can also help a patient to keep healthy. Doctors have found that hobbies are useful in helping patients (病人) recover from illness. Hobbies give patients who can't move around something to do, and provide interests that keep them from thinking about themselves. Many hospitals treat (治疗) patients by having them take up interesting hobbies. Anyone, old or young, sick or well, rich or poor, can follow a good hobby, in spite of his age, health or money.

    In early times, most people were too busy making a living to have many hobbies. But some persons who had spare time did enjoy hobbies. People today have more time than ever before for hobbies. Machines have now reduced much time that people must spend on their jobs. More people retire at an earlier age than before. Those who have developed hobbies never need to worry about what to do with their newly-found free time hours.

    Sir William Osler, a famous Canadian doctor expressed the value of hobbies by saying, “No man is really happy or safe without a hobby. ”

B

    People often think of the North Pole(北极) and the South Pole as similar frozen(冰冻的) wastelands. They are both places with very cold temperatures and few people live there. However, the North and South Poles are not much alike as people may imagine.

    The North Pole has no land, only thick ice. Temperatures seldom go above 32°F, at which water turns into ice. Most of the time, it stays below zero. In winter temperatures are usually as low as -30°F.

    Although conditions were very poor, people tried for many centuries to reach the North Pole. About 100 years ago, two men, Robert Peary and Mathew Henson, were able to get to this environment full of troubles and difficulties. They reached the North Pole on March 8th, 1909. It was really a hard trip for them.

    There are few things more dangerous than crossing the Arctic(北极圈) on foot. People who stayed there may face many problems: very cold temperatures, sudden storms, and even hunger. Most of the area is uninhabited. Few people can live in such a difficult place.

    People might think that with such low temperatures for most of the year, the ice would be thick and hard. However, this is not true in the Arctic. The movement of the ocean water under the ice may often cause many different changes on the surface. Sometimes the ice breaks into two opening lanes of water(水道) called “leads”. Anyone who falls into a lead can be frozen to death in a few minutes.

    Most of us know that Ikea is the world's biggest furniture company. However, did you know that it's also a pioneer in environmental protection?

    Ikea says it's working hard to improve the environment. The company has made huge efforts to cut the carbon emissions(碳排放)of its suppliers(供应商).Over the past five years, Ikea has helped its suppliers become 18 percent more energy-efficient. It managed to do so by bringing its suppliers together. The one that produces the least carbon emissions will be praised.

    Ikea has also invested(投资)heavily in clean energy. The company now operates more than 300 wind turbines(叶轮机)around the world. It has also set up nearly 750,000 solar panels(太阳能嵌板)on the roof of its stores. As a result, Ikea can produce 71 percent of the energy it uses, which are all from clean sources. In some countries，such a} Denmark and Finland，the company produces as much energy as it uses.

    Ikea has been buying forests as well. It owns nearly 750 square kilometers of forest.

    Last but not least, Ikea has tried changing customers' behavior(行为).It does so by improving product designs. In 2015, Ikea changed all of its lighting products into LED. This change alone, it says, has saved lots of electricity.

    If you go shopping in any toy store, you can see clearly the differentgames and toys for boys and girls: there are a lot of pink toys on one side ofthe store for girls; and dark colored cars, guns, and soldiers for boys. Somebig stores with toys may even have a pink floor for girls and a blue floor forboys. In fact, it is difficult to buy a toy for a girl that is not pink.

    Somepeople think that too much pink is bad for girls. Sue Palmer, writer of ToxicChildhood, is very worried that most girls over the age of three are crazyabout the color. According to some scientists, this happens for two reasons. Firstly,most companies offer too many products in pink. Also, many parents think theirlittle daughter looks cute in pink. Sue Palmer says that girls at this agecannot make proper decisions by themselves, but the pink can affect (影响) the choices and thedecisions they will make in the future.

    Someparents are worried too-for example, Vanessa Holburn, thirty-two, who has twogirls under the age of four. Their bedrooms are a sea of pink and Vanessa isnot happy. "Pink says that you are soft and gentle. Blue says that you arestrong and powerful. I want my daughters to be strong and powerful. I'm worriedthat pink will not help them with that,"she says.

    Butnot everyone thinks there's something wrong with pink. Grayson Turner is afather of three girls and he isn't worried at all. "People forget thatthings change all the time," he says. "My girls used to love pink whenthey were little, but as they get older, they change." Turner explainsthat his twelve-year-old daughter never wears pink clothes anymore. "Thislove of pink is just a fashion and all fashions change," he adds. "It'sonly since the 1940s that people have started dressing girls in pink-beforethat it was a color for boys."