题目内容
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[单选题]
从油气分离效果上看,对于一般的油田,采用()级分离经济效益最好。
A.一级或二级
B.二级或三级
C.三级或四级
D.四级或五级
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A.一级或二级
B.二级或三级
C.三级或四级
D.四级或五级
A.旅游,可以认为是一个活动,一种行为,一段体验,一种现象,一种社会关系,以及一系列的经济往来关系
B.从认识论和方法论上看,“什么是旅游”可以描述,“旅游是什么”却很难准确界定
C.“什么是旅游”是对某一属性的判定,可以采用归纳法,即从个别事例出发,一系列特定事实的观察,总结、归纳出一种模式或规律
D.“旅游是什么”揭示的是旅游的本质,需要运用演绎法,首先抽象出理论,再到实践中去检验,然后再根据实践反馈对于理论进行再抽象和再提炼
从理论渊源上看,我们过去对于财政的认识与()有关。
A凯恩斯主义
B马克思主义
C无政府主义
D马太效应
根据气力输送的特点,降低动力消耗,节约能源是一个重要的研究课题,从经验中知,管道内径是关于能耗的重要参数。直观上看,当输送量一定时,管径过小,输送易阻滞,管径过大,虽输送畅通,但又造成能量的浪费。根据经验,把管径分成三组,各组的试验结果如下表所示,试用方差分析法比较各组的效果.
管径(mm) | 单位功耗 |
230 | 0.0308,0.0476,0.0504 |
250~260 | 0.0532,0.032,0.0218,0.028,0.028, 0.042,0.0336,0.042,0.042,0.028 |
280~320 | 0.07,0.07,0.0644,0.0312,0.0756,0.0756, 0.07,0.0588,0.0588,0.042,0.0308,0.0364, 0.0448,0.21,0.154,0.1064,0.1288,0.112, 0.1064,0.1288,0.0756,0.0644,0.0504,0.0644, 0.0504,0.0308 |