某医院临床实验室为了配合甲型H1N1流感诊治的需要，拟开展甲型H1N1流感病毒核酸检测,甲型H1N1病毒分离鉴定,血,尿,粪常规检测,生化常规检测,血气分析,T细胞亚群分析等工作，医院为实验室配备了一台A2型生物安全柜，为工作人员准备了一定数量的防护用品，疑似甲型H1N1流感患者的样本由专人进行运送。
进行甲型H1N1病毒核酸检测人员的最佳个体防护应为
A:穿工作服,戴外科口罩 B:穿工作服，戴N95口罩 C:穿工作服,隔离衣或连体衣，戴帽子,外科口罩 D:穿工作服,隔离衣或连体衣，戴帽子,外科口罩,单层一次性手套，穿不露脚趾的实验鞋 E:穿工作服,隔离衣或连体衣，戴帽子,N95口罩,双层手套，鞋套或专用实验鞋，护目镜或面罩 F:工作服即可
FDA: Human, Animal Waste Threatens Produce
The biggest food safety risk for fresh fruits and vegetables as they are grown, picked or processed comes from human and animal waste, the US Food and Drug Administration （FDA）1 said Friday.
More than 9, 000 Americans die each year from food-borne diseases and some scientists believe fresh produce is the biggest carrier of contamination.2
The FDA issued a set of draft guidelines for U. S. and foreign growers to carefully monitor worker hygiene, water quality, manure management and transportation.3
This 34-page draft guidelines urged growers to give workers lessons on basic hygiene such as using soap to wash their hands, covering wounds that could come into contact with produce4, and using only clean toilets.
The FDA guidelines identified “the major source of contamination ”for fresh produce as human or animal feces.
“We think just proper controls and proper attention to detail would make a big difference in food safety,” 5 said and FDA official, “It is our belief that these guidelines would not be very costly.” 6
But grower groups disagreed with the FDA"s assessment. “Most food-borne disease outbreaks that happen further down the distribution line are due to contamination because people preparing food are not properly washing their hands, ”said Stacey Zawal, an official with United Fresh Fruit and Vegetable Association. “That is not necessarily true for growers and packers.”7
Some US grower organizations have expressed concern that the agency is interfering with on-farm practices. 8 Others object to the FDA"s proposal to have growers formally document the picking, handling and transportation of produce so that health officials could quickly recall foods if necessary.9
Consumer groups criticized the FDA guidelines as of little use because they will not carry the force of law.10 But stricter regulations could evolve as researchers find new technology or methods to kill harmful bacteria or parasites, the FDA said.
The FDA recommendations are due to be made final by the FDA later this year for use by US and foreign growers. The matter of encouraging foreign growers to adopt the guidelines remains somewhat tricky11 but FDA officials say it is vital because of the huge amount of imported produce.
词汇：
contamination/ kənˌtæmɪ"neɪʃən/n. 弄脏，污染，玷污
guideline / ˈgaɪdlaɪn/n.指导方针，准则，标准
manure/ məˈnjʊə/n. 肥料，粪肥
document / "dɒkjʊmənt/vt.用文件证明；为……提供文件
feces / "fi:si:z/n.粪便，排泄物
recall/ rɪˈkɔ:l/vt. 收回，撤销；记得，回想起
parasite / "pærəsaɪt/n.寄生生物；寄生虫
tricky / ˈtrɪki/adj.需慎重对待的，难对付的，微妙的，难以捉摸的；诡计多端的，狡猾的
Consumer groups criticized the FDA guidelines because they didn"t think that these guidelines____
A:had won enough support from the farmers B:had been written with strict regulations C:would surely be carried out D:included new technology
Older Volcanic Eruptions
Volcanoes were more destructive in ancient history, not because they were bigger, but because the carbon dioxide they released wiped out life with greater ease.
Paul Wignall from the UniversityofLeedswas investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals, but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise, the older the massive volcanic eruptions were, the more damage they seemed to do. He calculated the "killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava that they produced. He found that size for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.
The Permian extinction 1, for example, which happened 250 million years ago, is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide. The global warming that followed wiped out 80 per cent of all marine genera at the time, and it took 5 million years for the planet to recover. Yet 60 million years ago, there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within ten thousands of years. "The most recent ones hardly have an effect at all," Wignall says. He ignored the extinction which wiped out the dinosaurs 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid. He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.
Vincent Courtillot, director of the Paris Geophysical Institute inFrance, says that Wignall"s idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced, and that lava volume may not necessarily correspond to carbon dioxide emissions.
词汇：
dioxide [daɪˈɒksaɪd] n. 二氧化物
lava ["lɑ:və] n. 熔岩
Permian [ˈpə:miən] adj. 二叠纪
gigaton ["dʒɪgətʌn] n. 十亿吨梯恩梯
genera ["dʒenərə] n. 种类
dinosaurs ["daɪnəsɔ:z] n. 恐龙
asteroid [ˈæstərɔɪd] n. 小行星
注释：
1.The Permian extinction:二叠纪物种灭绝
Why did older volcanic eruptions do more damage than more recent ones？
A:Because they killed off life more easily. B:Because they were brighter. C:Because they were larger. D:Because they were hotter.
已知x（n）=1，其N点的DFT［x（n）］=X（k），则X（0）=（）。
A:N B:1 D:-N
已知x（n）=δ（n），其N点的DFT［x（n）］=X（k），则X（N-1）=（）。
A:N-1 B:1 D:-N+1
已知n=n1+n2，则（）。
A:（F／P，i，n）=（F／P，i，n1）+（F／P，i，n2） B:（F／P，i，n）=（F／P，i，n1）×（F／P，i，n2） C:（P／F，i，n）=（P／F，i，n1）+（P／F，i，n2） D:（P／F，i，n）=（P／F，i，n1）×（F／P，i，n2）
retun n*Fun(n-1);
A:int Fun(ira n) B:int Fun(int n) C:int Fun(int n)
下列程序段的执行结果为______。 Dim n As Integer n=10 While n ＜＞ 0 n=n-1 Wend Print "n="; n
A:n=0 B:n=1 C:False D:n=-1
单选集
