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Questions 17 and 18 are based on the following news. At the end of the news item, you will be given 10 seconds to answer each of the two questions. Now listen to the news. What does the news item say about Richard Nafzger（）
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三个进程P1、P2、P3互斥使用一个包含N（N＞0）个单元的缓冲区。P1每次用produee（）生成一个正整数并用put（）送入缓冲区某一空单元中；P2每次用getodd（）从该缓冲区中取出一个奇数并用countodd（）统计奇数个数；P3每次用geteven（）从该缓冲区中取出一个偶数并用eounteven（）统计偶数个数。请用信号量机制实现这三个进程的同步与互斥活动，并说明所定义的信号量的含义。要求用伪代码描述。
生活中清洗餐具的“洁洁灵”是一种污染源，会影响人的健康。为了说明这一问题，特设计了如下实验： 实验目的：观察不同浓度的“沽洁灵”溶液对草履虫生活状态的影响程度。 实验材料及用具：草履虫培养液、已培养若干天的草履虫、蒸馏水、脱脂棉、吸管、“洁洁灵”、量筒、小烧杯、大烧杯、玻璃棒、培养皿，解剖镜两台和计数器。 请帮助完成实验步骤的设计，并回答问题。 实验步骤： 第一步：配制100×10-6、20×10、10×10-6、2×10-6的“洁洁灵”溶液，分别标以2号、3号、4号、5号标签。 第二步：______。 第三步：______。 实验现象记录如下表(每份样品观察20个草履虫)： 培养液号 1 2 3 4 5 “洁洁灵”浓度 0 100×10-6 20×10-6 10×10-6 2×10-6 生存状况 全部自由生活 全部死亡 5个存活 17个存活 全部存活 运动迅速 静止不动 运动缓慢 运动缓慢 运动迅速 由此结论可推出对我们生活的启示是：______。
突变型面包霉常需要在基本培养基上添加适当的氨基酸才能生长。现在用两种氨基酸依赖型红色面包霉突变株a和b，分别接种到下面的6种培养基上，两种突变株都不能在1、3、5号培养基上生长，a、b可以分别在2、4和2、6号培养基上生长。各种培养基的成分如下表。关于突变株a和b分别对于A～J中氨基酸需求的说法，正确的是( ) 培养基 1 2 3 4 5 6 添加氨基酸 BCDE BEFG CFHI DEFI GHIJ EHCJ
TEXT BWilfred Emmanuel-Jones was a teenager before he saw his first cow in his first field. Born in Jamaica, the 47-year-old grew up in inner-city Birmingham before making a career as a television producer and launching his own marketing agency. But deep down he always nurtured every true Englishman’s dream of a rustic life, a dream that his entrepreneurial wealth has allowed him to satisfy. These days he’s the owner of a thriving 12-hectare farm in deepest Devon with cattle, sheep and pigs. His latest business venture: pushing his brand of Black Farmer gourmet sausages and barbecue sauces. "My background may be very urban," says Emmanuel-Jones. "But it has given me a good idea of what other urbanites want."And of how to sell it. Emmanuel-Jones joins a herd of wealthy fugitives from city life who are bringing a new commercial know-how to British farming. Britain’s burgeoning farmers’ markets—numbers have doubled to at least 500 in the last five years—swarm with specialty cheesemakers, beekeepers or organic smallholders who are redeploying the business skills they learned in the city. "Everyone in the rural community has to come to terms with the fact that things have changed." Says Emmanuel-Jones. "You can produce the best food in the world, but if you don’t know how to market it, you are wasting your time. We are helping the traditionalists to move on."The emergence of the new class of superpeasants reflects some old yearnings. If the British were the first nation to industrialize, they were also the first to head back to the land. "There is this romantic image of the countryside that is particularly English," says Alun Howkins of the University of Sussex, who reckons the population of rural England has been rising since 1911. Migration into rural areas is now running at about 100,000 a year, and the hunger for a taste of the rural life has kept land prices buoyant even as agricultural incomes tumble. About 40 percent of all farmland is now sold to "lifestyle buyers" rather than the dwindling number of traditional farmers, according to the Royal Institution of Chartered Surveyors.What’s new about the latest returnees is their affluence and zeal for the business of producing quality foods, if only at a micro-level. A healthy economy and surging London house prices have helped to ease the escape of the would-be rustics. The media recognize and feed the fantasy. One of the big TV hits of recent years, the "River Cottage" series, chronicled the attempts of a London chef to run his own Dorset farm.Naturally, the newcomers can’t hope to match their City salaries, but many are happy to trade any loss of income for the extra job satisfaction. Who cares if there’s no six-figure annual bonus when the land offers other incalculable compensationsBesides, the specialist producers can at least depend on a burgeoning market for their products. Today’s eco-aware generation loves to seek out authentic ingredients. "People like me may be making a difference in a small way," Jan McCourt, a onetime investment banker now running his own 40-hectare spread in the English Midlands stocked with rare breeds.Optimists see signs of far-reaching change: Britain isn’t catching up with mainland Europe; it’s leading the way. "Unlike most other countries, where artisanal food production is being eroded, here it is being recovered," says food writer Matthew Fort. "It may be the mark of the next stage of civilization that we rediscover the desirability of being a peasant." And not an investment banker. Which of the following does NOT contribute to the emergence of a new class of farmers（）
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