Europe is now the biggest market for organic food in the world, having grown by 25  percent a year over the past 10 years. Denmark's agriculture minister is herself an organic farmer. The UK market for organic food grew by 55 percent in 2000, while the food market as a whole grew by only one percent. Yet only seven percent of British shoppers account for nearly 90 percent of organic sales. However popular the idea of organic farming may be, it is still an interest for only a few people.

    So what makes the idea of organic farming popular? Organic farming means farming with natural materials, rather than with man-made fertilizers or pesticides. Organic farmers rely on many  methods — such as crop rotation (农作物的轮作) and the use of resistant varieties, because they are necessary for organic farmers to compensate for the shortage of man-made chemicals.

    Organic farming is often supposed to be safer than traditional farming for the environment. Yet after a long research on organic farming worldwide for a number of years, science continues to be against this opinion. The House of Commons committee on agriculture publicized that, even with complete research work, it would fail to find any scientific evidence to prove “that any of claims （宣称） made for organic farming is always true”.

    However, the talk about the benefits of organic farming is going on. This is partly because many people depend on their individual farm, the soil, the weather, and so on.

    Self-driving vehicles will rely on cameras, sensors and artificial intelligence (AI) to recognize and respond to road and traffic conditions, but sensing is the most effective for objects and movement in the neighborhood of the vehicle. Not everything important in a car's environment will be caught by the vehicle's camera. Another vehicle approaching at high speed on a collision (碰撞) track might not be visible until it's too late. This is why vehicle-to-vehicle communication is undergoing rapid development. Our research shows that cars will need to be able to chat and cooperate on the road, although the technical challenges are considerable.

    Applications for vehicle- to-vehicle communication range from vehicles driving together in a row, to safety messages about nearby emergency vehicles. Vehicles could alert each other to avoid collisions or share notices about passers-by and bicycles.

    From as far as several hundred meters away, vehicles could exchange messages with one another or receive information from roadside units (RSUs) about nearby incidents or dangerous road conditions through 4G network. A high level of AI seems required for such vehicles, not only to self-drive from A to B, but also to react intelligently to messages received. Vehicles will need to plan, reason, strategize and adapt in the light of information received in real time and to carry out cooperative behaviors. For example, a group of autonomous vehicles might avoid a route together because of potential risks, or a vehicle could decide to drop someone off earlier due to messages received, a foreseen crowding ahead.

    Further applications of vehicle- to-vehicle communication are still being researched, including how to perform cooperative behavior.

    Languages have been coming and going for thousands of years, but in recent times there has been less coming and a lot more going. When the world was still populated by hunter-gatherers, small, tightly knit(联系) groups developed their own patterns of speech, independent of each other. Some language experts believe that 10,000 years ago, when the world had just five to ten million people, they spoke perhaps 12,000 languages between them.

    Soon afterwards, many of those people started settling down to become farmers, and their languages too became more settled and fewer in number. In recent centuries, trade, industrialization, the development of the nation-state and the spread of universal compulsory education, especially globalization and better communications in the past few decades, all have caused many languages to disappear, and dominant languages such as English, Spanish and Chinese are increasingly taking over.

    At present, the world has about 6,800 languages. The distribution of these languages is hugely uneven. The general rule is that mild zones have fewer languages spoken by many people while hot, wet zones have more, often spoken by small numbers. Europe has only around 200 Languages: the Americas about 1,000, Africa 2,400; and Asia and the Pacific perhaps 3,200, of which New Guinea alone accounts for well over 800. The median number(中位数) of speakers is a mere 6,000, which means that half the world's languages are spoken by fewer people than that.

    Now over 400 of the total of 6,800 languages are close to extinction(消亡), with only a few elderly speakers left. None of these seems to have chances of survival.

    OK, so it's not a real war but the U. S. and China are at the beginning of a trade war thanks to President Trump's policy. The Chinese government raised $34 billion in new duties on goods exported from the U.S. last week in answer to President Trump's unwise tariffs(关税) of $34 billion on Chinese goods.

    Farm and seafood-producing states are going to be hit hardest by China's new tariffs on U. S. goods. States where cars are made and shipped to China are on the hook as well.

    In terms of value, some 38 percent of products on the tariff list are agricultural, including soybeans, sorghum, tobacco and meat. That's nothing like good news for farm-belt states, primarily in the Midwest like Iowa.

    A wide range of seafood is on China's tarifflist. That could hurt fishery workers in Alaska and lobster(龙虾) harvesters in Maine. Alaska, for example, exported nearly $lbillion worth of seafood to China. "China is a major market for Alaska seafood," said Alexa Tonkovich, Executive Director of the Alaska Seafood Marketing Institute. "The seafood industry directly employs nearly 60,000 workers in Alaska each year and directly employs more workers than any other private industry."

    And automaking States, particularly in the South, are also at risk. Some 24 percent ofproducts on the list- in terms of value-are cars, trucks and other vehicles. Michigan alone exported $1.7 billion worth of motor vehicles and vehicle parts to China in 2017. Other states being affected include South Carolina, where BMW makes SUVs for both the U.S. and export, and Alabama, home to Mercedes-Benz, Toyota, Honda and Hyundai factories.

    This round of tariffs spares some industries, like commercial aircraft. Washington State could breathe a sigh of relief, which is home to Boeing. It also, for the moment, skips tariffs on chemical products.

    Alexa Tonkovich has warned the U.S. government that the trade war could risk jobs, reduce industry profits, and cause higher prices for consumers in the U.S!

    Throughout history scientists have risked their health and their lives in their search for the truth.

    Sir Isaac Newton, the seventeenth century scientist, was very smart, but that didn't stop him from doing some pretty stupid things. In his laboratory in Cambridge he often did the strangest experiments. Once, while testing how light passes through lenses (晶状体), he put a long needle into his eye, pushed it to the back, and then moved it around just to see what would happen. Luckily, nothing long-lasting did. On another occasion he stared at the sun for as long as he could bear, to discover what effect this would have on his sight. Again he escaped suffering permanent damage, though he had to spend some days in a darkened room before his eyes recovered.

    In the 1750s the Swedish chemist Karl Scheele was the first person to find a way to produce phosphorus (磷). He in fact discovered eight more chemical elements including chlorine (氯), though he didn't get any praise for them. He was a very clever scientist, but his one failing was a curious habit of tasting a little of every substance he worked with. This risky practice finally caught up with him, and in 1786 he was found dead in his laboratory surrounded by a large number of dangerous chemicals, any of which might have been responsible for his death.

    Eugene Shoemaker was a respected geologist. He spent a large part of his life studying craters (火山口) on the moon, and how they were formed, and later did research into the comets of the planet Jupiter. In 1997 he and his wife were in the Australian desert where they went every year to search for places where comets might have hit the earth. While driving in the Tanami desert, normally one of the emptiest places in the world, another vehicle crashed into them and Shoemaker was killed on the spot. Some of his ashes (骨灰) were sent to the moon aboard the Lunar Prospector spacecraft and left there — he is the only person who has had this honor.

    It is common to see many different kinds of insects while spending time outside in the summer. Some of them do not trouble people and can even add beauty to the natural environment. Other insects can harm the environment or humans. The population of these insects seems to stay large and healthy.

    But scientists say this does not appear to be true for some flying insects that serve an important purpose. There is growing evidence that these insects are decreasing across the world.

    One researcher looking into the present insect population is Doug Tallamy, a professor at the University of Delaware. He remembers walking through Washington D. C., in the past when it was "alive with insects, especially butterflies". Now, he said, "The flying insects are actually gone." Wilson said this point seemed to be proved during a drive he made last year from Boston to Vermont. He was surprised that, during his trip, he counted only one insect that had hit the car's front window. Several other scientists have carried out similar tests by checking how many insects hit their cars while traveling.

    While researchers admit this method is not scientific, they say it can still help them understand the changing flying insect population. There have not been many studies done on the flying insect populations covering large areas. However, some international research suggests a downward turn. In 2006, a group of studies showed that there had been a 14-percent drop in ladybugs(瓢虫) in the United States and Canada from 1987 to 2006. In Germany, a 2017 study found an 82-percent drop in the number of flying insects compared to levels recorded in 1990.

    After the German study, other countries also started looking into the problem. David Wagner of the University of Connecticut says other evidence leads him to believe the findings of the 2017 study are "clearly not a German thing".