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建筑工程施工安全技术 搅拌机在使用前要空车运转，检查各机构的离合器及制动装置情况，不得在运行中______。
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Psychologist George Spilich and colleagues at Washington College in Chestertown, Maryland, decided to find out whether, as many smokers say, smoking helps them to "think and concentrate". Spilich put young non-smokers, active smokers and smokers deprived(被剥夺) of cigarettes through a series of tests. In the first test, each subject(试验对象)sat before a computer screen and pressed a key as soon as he or she recognized a target letter among a grouping of 96. In this simple test, smokers, deprived smokers and nonsmokers performed equally well The next test was more complex, requiring all to scan sequences of 20 identical letters and respond the instant one of the letters transformed into a different one. Non-smokers were faster, but under the stimulation of nicotine(尼古丁), active smokers were faster than deprived smokers. In the third test of short-term memory, non-smokers made the fewest errors, but deprived smokers committed fewer errors than active smokers. The fourth test required people to read a passage, then answer questions about it. Non-smokers remembered 19 percent more of the most important information than active smokers, and deprived smokers bested those who had smoked a cigarette just before testing. Active smokers tended not only to have poorer memories but also had trouble separating important information from insignificant details. "As our tests became more complex", sums up Spilich, "non-smokers performed better than smokers by wider and wider margins". He predicts, "Smokers might perform adequately at many jobs until they got complicated. A smoking airline pilot could fly adequately if no problems arose, but if something went wrong, smoking might damage his mental capacity". George Spilich"s experiment was conducted in such a way as to ______.
建筑工程施工安全技术 建筑施工最大的特点就是______。
机械制造场所安全技术中，关于车间安全通道的一般要求，下列叙述正确的有______。
建筑工程施工安全技术 随着建筑施工技术的发展，脚手架的种类也越来越多，按搭设的用途，可分为______。
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