题目

如图所示电路由交变电流供电，如果交变电流的频率升高，则(  )A.电容器的电容增大                  B.电容器的容抗增大C.电路中的电流增大                  D.电路中的电流减小 答案：C Bob insisted that he ________ nothing wrong and ________ from work． [　　] A． did; won’t be fired B． had done; not be fired C． should do; mustn’t be fired D． do; shouldn’t be fired