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判断对错.

12.15÷0.3=4.5

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    As the world's population grows, farmers will need to produce more and more food. And large farms are increasingly using precision farming to increase yields (产量), reduce waste, and reduce the economic and security risks that inevitably accompany agricultural uncertainty.

    Traditional farming relies on managing entire fields—making decisions related to planting, harvesting, irrigating, and applying pesticides and fertilizer (农药和化肥)—based on regional conditions and historical data. Precision farming, by contrast, combines sensors, robots, GPS, mapping tools and data-analytics software to customize(量身定制)the care that plants receive without increasing labor. Robot-mounted sensors and camera-equipped drones (无人机) wirelessly send images and data on individual plants to a computer, which looks for signs of health and stress. Farmers receive the feedback in real time and then deliver water, pesticide or fertilizer in adjusted doses(剂量)to only the areas that need it. The technology can also help farmers decide when to plant and harvest crops.

    As a result, precision farming can improve time management, reduce water and chemical use, and produce healthier crops and higher yields—all of which benefit farmers' bottom lines and conserve resources while reducing chemical runoff.

    Many small businesses are developing new software, sensors, and other tools for precision farming, as are large companies such as Monsanto, John Deere, Bayer, Dow and DuPont. The U.S. Department of Agriculture, NASA and the National Oceanic and Atmospheric Administration all support precision farming, and many colleges now offer course work on the topic.

    In a related development, seed producers are applying technology to improve plant characteristics. By following individual plants over time and analyzing which ones flourish in different conditions, companies can relate the plants' response to their environments with their genomics (基因组学). That information, in turn, allows the companies to produce seed varieties that will grow well in specific soil and weather conditions. This advanced technology may also help to improve crop nutrition.

    Farmers do not universally welcome precision agriculture for various reasons, such as high equipment costs and lack of access to the Internet. The technology may bring great challenges to experienced farmers who are not good at computers. And large systems will also be beyond the reach of many small farming operations in developing nations. But less expensive, simpler systems could potentially be applied. For others, though, cost savings in the long run may reduce the financial concerns. And however reticent some farmers may be to adopt new technology, the next generation of farmers are likely to warm to the approach.

同类题5

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“旮旯”一词探源

       “旮旯”是北方居民生活中常用的一个词,指屋子里或院子里的角落,或指一切角落。近年,北京艺人演出了话剧《旮旯胡同》,说的就是北京的一个不起眼的小巷子里发生的故事。

       “旮旯”这个词应该是阿尔泰语系的语言音译过来的,它的原意是表示居住地。今天的蒙古族居住地还有很多这样的地名,它们是与旮旯一词发音类似的词,像锡林格勒盟、霍林格勒市等。旮旯、格勒发音相似,写法不同,语源应该是相同的。汉语中使用“旮旯”一词的地区,正是我国长城沿线及华北、东北地区,是汉族与阿勒泰语系诸族长期相伴生活的地区,他们的语言影响了汉语是可想而知的。现在的北京方言中就有大量的蒙、满语词,如“窟窿”,即借用蒙古族语“库伦”(蒙语语意为围起来的地方)一词,都表示小的空间,汉语在词意上有所变化。

       那么,汉族是怎样借用“旮旯”这个词的呢?又怎样把它由表示重要的居住地的词,演变成一个表示边远小地方以至角落的呢?我想从我们现实生活的一些词汇演化过程,推测出过去演化的情况。例如,我们原本郑重地称来到中国的外国人为国际友人、外宾、外国人,后来,外国人越来越多,民间就称他们为“老外”了。“旮旯”一词的演变也应该符合这个规律。开始,阿勒泰语系某族人来到汉地,问他们从何处来,他们自然说某某格勒。后来,来的人多了,都说是来自某某格勒。时间长了,就演化为不发达的鲜为人知的边远、偏僻的地方,语音也打趣地变为“旮旯”。

       汉语里借用“旮旯”一词,可以单称旮旯,也可以和汉语里原来的词结合,叫犄角旮旯。从字形上看,能推测其音译自外族语。两个字不能拆开,这是很多外来语词的共同特点,如葡萄、唢呐、珐琅等。

       在阿勒泰语系中,“旮旯”表示宏大、雄伟、神圣的地方,从当初造字的字形上也能看出来。两个字都有日字。汉语中“旮旯”的本意是太阳的故乡或太阳神的住地,保持了阿勒泰语的原意。阿勒泰语系诸族,普遍有崇拜太阳神的信仰。但“旮旯”这个词译过来后,又经过演变,词意由神圣变为世俗,所指的地方也由大变小,但字形却没有变。