问题
单项选择题
永磁直流伺服电动机的工作曲线分为三个区域,其中Ⅱ区为( )。
A.加减速区
B.瞬间工作区
C.连续工作区
D.断续工作区
答案
参考答案:D
解析:试题解析:永磁直流伺服电动机的工作曲线分成三个区域:Ⅰ区为连续工作区;Ⅱ区为断续工作区;Ⅲ区为加速和减速区。
永磁直流伺服电动机的工作曲线分为三个区域,其中Ⅱ区为( )。
A.加减速区
B.瞬间工作区
C.连续工作区
D.断续工作区
参考答案:D
解析:试题解析:永磁直流伺服电动机的工作曲线分成三个区域:Ⅰ区为连续工作区;Ⅱ区为断续工作区;Ⅲ区为加速和减速区。
I’ll remember the first carnival(狂欢节). 小题1:. My parents came from Jamaica and they helped to start carnival. We had very little money, but we made costumers from old bits of material and feathers, and colourful masks. We decorated old lorries, so that we could ride on them through the streets. It took us six months to get ready. But on the big day, all our hard work had been worth it. People of all ages, from babies to grandparents, black and white, danced together in the street. 小题2:. The music was played on anything made of metal: it was very noisy. There were people watching from the windows of every house. We ate all our favourite Jamaican food, washed down with beer.小题3:– but carnival helps you forget the weather! When the carnival got too big, those old streets became too narrow for such big crowds(人群). Some people said they felt frightened by the large crowds and the noise. We were worried that carnival would be banned(禁止). Then we found an answer – everything was moved to a wider and safer street. 小题4:.
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