范仲淹的《岳阳楼记》中哪个成语泛指忧愁失意的文人？
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下列几种真空装置中，（）产生的真空度最易受季节影响。
A. 蒸汽喷射泵
B. 水力喷射泵
C. 干式真空泵
D. 水环真空泵
The greatest effect on stability occurs from loose liquids flowing（）.
A. from side to side in the tanks of the vessel
B. from fore to aft in the tanks of a vessel
C. in and out of a vessel that is holed in a wing tank
D. in and out of a vessel that is holed in a peak tank
每日总部以（）、（）两种方式发布全网监控大值班日报。
几何光学三个基本定律是：直线传播定律，反射定律，（）
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