机械密封与填料密封相比()的功率消耗较大。A、机械密封 B、填料密封 C、差不多

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问题:

机械密封与填料密封相比()的功率消耗较大。

A、机械密封

B、填料密封

C、差不多

考点:化工总控工考试化工总控工中级化工总控工中级题库
题型:单项选择题

500kV变电站站用电源接法最不合理的是()。

A.由主变压器第三绕组引接;

B.有较低电压母线时,从这类母线上引接两个站用电源;

C.无较低电压母线时,直接从高压母线上引一台站用变压器;

D.由附近的发电厂或变电站低压母线引接

题型:单项选择题

important, friend, mean, them, stand, itself, child, remember, age, weather, pleasant, feel
 
Have you heard of small talk? It 小题1:________ that the conversation is about some little things, which are not 小题2:________. You can make small talk when 小题3:_________ in line in the supermarket or while waiting for the bus. Though the topics in small talk aren’t important, small talk 小题4:________ is very important. It makes people 小题5:_________relaxed; It breaks the silence; It shows 小题6:________ and good manners; And it makes time pass 小题7:________.
In small talk, it’s important 小题8:________ to smile and keep the conversation relaxed. It’s also good to show a sense of humor. You could talk about the 小题9:_________ , an interesting story on TV, a sports event, a play or a movie, and you could ask parents about their 小题10:_________.
题型:单项选择题

电子质量为m,电荷量为e,从坐标原点O处沿xOy平面射入第一象限,射入时速度方向不同,速度大小均为v0,如图所示。现在某一区域加一方向向外且垂直于xOy平面的匀强磁场,磁感应强度为B,若这些电子穿过磁场后都能垂直射到荧光屏MN上,荧光屏与y轴平行,求:

(1)荧光屏上光斑的长度;

(2)所加磁场范围的最小面积。

题型:单项选择题

诊断急性阑尾炎时,下列哪项最有诊断意义

A.腹肌紧张

B.结肠亢气试验阳性

C.腰大肌试验阳性

D.闭孔肌试验阳性

E.右下腹固定压痛点

题型:单项选择题

黄继光、邱少云等志愿军战士被誉为“最可爱的人”,他们的英雄壮举发生在: [ ]

A.抗美援朝战争中

B.解放战争中

C.抗日战争中

D.北伐战争中

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