问题 问答题 简答题

简述电控设备和配电设备的区别。

答案

参考答案:

电控设备的功能以控制为主,多用接触器、继电器等控制器,操作频率较高,控制电路比较复杂,具体传动控动方案也随用户要求变化较大;而配电设备的功能则以传输电能为主,多用刀开关、断路器、熔断器等配电设备,有时也用接触器(线路接触器),其操作频率低,控制电路比较简单,且主电路和辅助电路方案标准化程度高。

单项选择题
单项选择题

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(4)空应选择()

A.of

B.at

C.to

D.for