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问题 选择题

宣传“不要随地吐痰”主要是因为（　　）

A．要保持当地的文明水平

B．痰内含有唾液淀粉酶

C．痰迹影响环境美观

D．痰内含有灰尘粒和细菌

答案

气管和支气管的表面的黏膜上有腺细胞和纤毛，腺细胞分泌黏液，使气管内湿润，黏液中含有能抵抗细菌和病毒的物质．纤毛的摆动可将外来的灰尘、细菌等和黏液一起送到咽部，通过咳嗽排出体外形成痰．因此不要随地吐痰，以免传播病菌．

故选：D

单项选择题

People are indulging in an illusion whenever they find themselves explaining at a cocktail(鸡尾酒) party, say, that they are "in computers," or "in telecommunications," or "in electronic funds transfer". The implication is that they are part of the high-tech world. Just between us, they usually aren’t. The researchers who made fundamental breakthroughs in those areas are in a high-tech business. The rest of us are（）of their work. We use computers and other new technology components to develop our products or to organize our affairs. Because we go about this work in teams and projects and other tightly knit working groups(紧密联系在一起的工作小组), we are mostly in the human communication business. Our successes stem from good human interactions by all participants in the effort, and our failures stem from poor human interactions. The main reason we tend to focus on the（）rather than the human side of the work is not because it’s more（）, but because it’s easier to do. Getting the new disk drive installed is positively trivial compared to figuring out why Horace is in a blue funk(恐惧) or why Susan is dissatisfied with the company after only a few months. Human interactions are complicated and never very crisp(干脆的,干净利落的) and clean in their effects, but they matter more than any other aspect of the work. If you find yourself concentrating on the（）rather than the（）, you’re like the vaudeville character(杂耍人物) who loses his keys on a dark street and looks for them on the adjacent street because, as he explains, "The light is better there!".

The rest of us are（）of their work.

A．creators

B．innovators

C．appliers

D．inventors
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单项选择题

采用矿用防爆型柴油动力装置，燃油的闪点应高于（）℃。

A、50

B、70

C、80

D、90
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