压在10kV及以下时,隔离开关可以进行拉、合电流小于70A的环路均衡电流操作。

题型:判断题

问题:

压在10kV及以下时,隔离开关可以进行拉、合电流小于70A的环路均衡电流操作。

考点:配电线路工配电线路(技师)配电线路(技师)题库
题型:判断题

阿波罗宇宙飞船上使用的是氢氧燃料电池,其电池总反应式为:2H2+O2=2H2O,电解液为KOH溶液,反应保持在较高温度使水蒸发,下列叙述中正确的是

A.工作时,电解质溶液的PH逐渐增大

B.工作时,能见到浅蓝色火焰

C.工作时,H2为正极,O2为负极

D.电极反应式为:负极:2H2+4OH―4e=4H2O正极:O2+2H2O+4e=4OH

题型:判断题

能证明SO2具有漂白性的实验是[ ]

A.SO2使酸性KMnO4溶液褪色   

B.SO2使溴水褪色

C.SO2使品红溶液褪色          

D.SO2使含酚酞的NaOH溶液褪色 

题型:判断题

以下对数字信号描述正确的是()

A.如果电信号参量携带离散消息,则这样的信号称为数字信号

B.如果电信号参量携带连续消息,则这样的信号称为数字信号

C.如果电信号参量携带规定幅度后的连续消息,则这样的信号称为数字信号

D.如果电信号参量携带规定频率后的连续消息,则这样的信号称为数字信号

题型:判断题

Looking back on my childhood, I am convinced (1) naturalists are born and not made. Although we were all brought (2) in the same way, my brothers and sisters soon gave up their pressed flowers and insects. (3) them, I had no ear (4) music and languages, I was not an early reader and I could not do mental arithmetic.Before World War I we (5) our summer holidays in Hungary. I have only the memory of the house we lived (6) , of my room and my toys. I can hardly (7) clearly the large family of grandparents, aunts, uncles and cousins who gathered (8) door. But I do have a clear memory of the dogs, the farm (9) , the local birds and, (10) all, the insects.I am a (11) , not a scientist. I have a p (12) of the natural world, and my enthusiasm has led me into varied investigation. I love discussing my favorite topics and enjoy (13)  the midnight oil  (14)  reading about other people’s observations and discoveries. Then  (15)  happens that brings these observations together  (16)  my conscious mind. Suddenly you fancy (想象), you see the answer  (17)  the riddle, and books, of which some might honor with the title of scientific research.But curiosity, a keen eye, a good memory and enjoyment of the animal and plant world do not make a scientist; one of the outstanding and essential  (18)  required is self-discipline, a quality I lack. A scientist requires not only  (19)  but also hard training, determination and a goal. A scientist, up to a point, can be made. A naturalist is  (20) . If you can combine the two, you get the best of both worlds.

 

第(12)空应选择()

A.wish

B.eagerness

C.imagination

D.love

题型:判断题

原子吸收光谱仪的操作的关机顺序是()。

A.关空气、关空心阴极灯、关总电源、关通风机、关乙炔气

B.关通风机、关空气、关空心阴极灯、关总电源、关通风机

C.关乙炔气、关空气、关空心阴极灯、关总电源、关通风机

D.关空心阴极灯、关总电源、关通风机、关空气、关乙炔气

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