阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    In an ideal world, people would not test medicines on animals. Such experiments are stressful and sometimes painful for animals, and expensive and time-consuming for people. Yet animal experimentation is still needed to help bridge vast gaps in medical knowledge. That is why there are some 50 to 100 million animals used in research around the world each year.

    Europe, on the whole, has the world's most restrictive (严格的) laws on animal experiments. Even so，its scientists use some 12 million animals a year, most of them mice and rats, for medical research. Official statistics show that just 1.1 million animals are used in research in America each year. But that is misleading. The American authorities do not think mice and rats are worth counting and, as these are the most common laboratory animals, the true figure is much higher. Japan and China have even less comprehensive (全面的) data than America.

    Now Europe is reforming the rules governing animal experiments by restricting the number of animals used in labs. Alternatives to animal testing，such as using human tissue or computer models, are now strongly recommended. In addition, sharing all research results freely should help to reduce the number of animals for scientific use. At present, scientists often share only the results of successful experiments. If their findings do not fit the hypothesis (假设) being tested, the work never sees the light of day. This practice means wasting time, money, and animals' lives in endlessly repeating the failed experiments.

    Animal experimentation has taught humanity a great deal and saved countless lives. It needs to continue，even if that means animals sometimes suffer. Europe's new measures should eventually both reduce the number of animals used in experiments and improve the way in which scientific research is conducted.

    Spring is a wonderful season to celebrate rebirth and new life. The long, cold winter is over. The weather is warmer and sunnier. The trees again have leaves and the flowers are blooming. The season represents hope, joy and beauty. At this time, many people think of this classical music piece—Spring, which shows happiness. Italian composer Antonio Vivaldi wrote it in the seventeen hundreds.

    However, not all songs about spring are happy. This song written and sung by K.D. Lang is about dreaming of spring in cold dark places. She recorded I Dream of Spring in 2008.

    Richard Rodgers and Oscar Hammerstein wrote It Might as Well Be Spring for the movie State Fair in 1945.Frank Sinatra sings it. It is a feeling of restlessness or excitement brought on by the coming of spring. Richard Rodgers also wrote Spring Is Here, this time with Lorenz Hart. Ella Fitzgerald sings this song about feeling lonely during this season.

    Frank Loesser wrote the sad song, Spring Will Be a Little Late This Year. Why has the season been delayed? Because the singer's lover has left her. Sarah Vaughn released(发行) her version of the song in 1953.

    By now you may be thinking, "Enough with the sad songs, already！"OK ,then how about a cowboy song? Gene Autry was one of the America's most famous singing cowboys. He recorded When It's Spring time in the Rockies in 1937.

    And finally, we'll leave you with a sunny song called Up Jumped Spring. Freddie Hubbard wrote this jazz song in 1977 and Billy Taylor Trio performs it.

    Scientists can figure out a movie's emotional tone from the gasps(喘气) of its audience. These gases could point the way to a subtle(微妙的，精细的) form of human communication, a new study suggests.

    "When you see a movie, you can hear the music and see the pictures. However, you don't realize here are chemical signals in the air. And they, too, could be affecting you, says Williams, who led the study. As an atmospheric chemist, he studies the chemical makeup of the air around us.

    Williams started out measuring the air in a soccer stadium. He noticed that levels of carbon dioxide and other gases changed wildly whenever the crowd cheered. That got him wondering -- Could the gases people breathe out be influenced by emotions?

    To find out, he went to the movies.

    Williams and his coworkers measured air samples collected over six weeks in two movie theaters. Overall, 9,500 movie goers watched 16 films. They included a mix of comedy, romance, action and horror films. Among them were The Hunger Games, Catching Fire, Carrie, and Walking with Dinosaurs. The researchers gave scenes from the movies such labels as "suspense(悬疑)", "laughter" and "crying". Then they looked for hundreds of chemicals in the air that showed up as people were watching particular movie scenes.

    And certain scenes had distinct chemical "fingerprints". Scenes that had people laughing or on the edge of their seats were especially distinctive. During screenings of The Hunger Games, levels of carbon dioxide and isoprene got to the highest at two suspenseful moments. Because isoprene is related to muscle movement, the researchers think tense movie moments likely led to its spikes(尖峰). Williams and his colleagues think the increase in carbon dioxide was due to the viewers' increased pulse and breathing rates.

    Scientists need more data to make stronger links between human emotions and what's in their breath. But Williams can see potential practical uses. Companies, for instance, could quickly measure the air during tests to see how people feel about new products. He pictures future studies recording other body variables(变数) as well. These might include heart rate and body temperature, for instance. "It's something to find out."

    Do you ever draw? Most of us don't. The reason we usually leave drawing to the artists is that we're not very good at it. Who wants to do anything they're bad at? {#blank#}1{#/blank#}. Studies have found drawing has many benefits, artist or not. Here are just a few reasons for picking up a pen or pencil of any kind.

    It pushes you to be patient. We're used to things happening fast these days. Drawing is not fast. {#blank#}2{#/blank#} That's OK, and as something comes together over time, you'll be reminded of the value of patience. Drawing is an object lesson that not everything good comes quickly, which is an easy thing to forget.

    {#blank#}3{#/blank#} A few of my drawings are really kind of great. Í can look at them with pride. But plenty of my little drawings ate nonsense or unfinished. It doesn't matter. I still have the experience of drawing and the benefits that brings. Even if you're not naturally "good" at drawing, you'll get better over time if you practice. {#blank#}4{#/blank#} Your drawing doesn't have to mean anything or do anything useful, Sometimes you will even fail. No big deal.

    It makes memories stick, I draw in order to capture (捕获) moments from my life. I'm not great at drawing, but that's not the point. Sometimes I draw the view from the window of my hotel room-whether it's a great view or not. Remember, the idea is to capture the moment, not create a masterpiece. Other times I draw from my dinner table. {#blank#}5{#/blank#}

    China and India are leaders in improving global(全球的) tree cover, a new study based on NASA research showed.

    They took a 31.8% part together of the total global new leaf area between 2000 and 2017. China played a major role, adding 25% to this increase, and India added 6.8%, followed by Canada and Russia. The study in the Nature Sustainability journal shows that more than 5.5 million square kilometers of green leaf area was added globally. Since 2000, there has been a five-percent increase in global green cover, it said.

    "The greening over the last twenty years shows an increase in leaf area on plants and trees which is as large as the area of the entire Amazon rainforest," Chi Chen, a Boston University researcher and lead of the study told Nature Sustainability. Large plantation activities to protect forests in China contributed nearly 42% to the country's green cover, and agriculture added another 32%. In India, 82% of the increase in leaf area was because of agriculture.

    "China and India take up one-third of the greening, but hold only nine percent of the planet's land area covered in green plants," Chi Chen told NASA Earth Observatory. "That is a surprising finding, considering the land degradation(退化) in countries with large populations."

    Boston University's research team first detected an increase in global green cover in the 1990s but were unsure about what contributed to the increase. Finally, with the help of NASA's Terra and Aqua satellites research, they managed to find out the increase in leaf cover from different areas and places.

    Every morning, Ben Mumford starts his school day with math. At the age of ten, he is already working at GCSE level, but he does not always bother to get out of his pajamas (睡衣裤) in time for the class. He reads more books than most of his friends, studies science on the beach, and recently built a go-kart (卡丁车) in a technology lesson. Ben is happy and fulfilled, all, his mother believes, thanks to homeschooling.

    Homeschooling is not what it used to be. What emerged in the 1970s as a way for Catholic (信天主教的) parents to infuse (灌输) religion into their kids' education is now probably the fastest-growing form of education in the U.K. The number of homeschooled children has risen by about 40 percent over three years. Here are a handful of reasons why homeschooling makes sense in the 21^st century.

    Contrary to the name, homeschooling takes place in an actual home only a small part of time. A great deal of instruction happens in libraries, museums and community colleges. These experiences have the effect of helping kids mature much more quickly and developing a trait of open-mindedness.

    The key idea of homeschooling is that kids need to learn at the speed, and in the style, most appropriate for them. Without formal curriculum to guide their education, homeschoolers get the chance to explore a range of topics that might not be normally offered until high school or college. They can study psychology in the fourth grade, or finance in the eighth grade.

    The most common misunderstanding about homeschoolers is that they lack social skills. However, social media makes it convenient for homeschoolers of today to have just as much opportunity to make friends as kids studying in traditional schools. Meanwhile, they do not need to deal with the potential problems of being around kids in a school environment, including bullying, which might result in anxiety and depression.

    For most people, school is really good, and it works for them because they learn in the way that school teaches. However, there are so many different ways of learning and processing (处理) information and knowledge. It does not necessarily work for everyone.