水泥砼加热型填缝料有()。 ["A、沥青玛蹄脂类 ","B、橡胶沥青类 ","C、乳化沥青橡胶类 ","D、聚(氨)脂类"]
某感应电动机额定转速为nN=980r/min,该电机的极对数及额定转差率分别为:() ["A、6,0.03","B、3,0.02","C、3,0.04","D、4,0.03"]
同步通信有什么特点?
什么是数字滤波?
起动并励直流电动机时,应() ["A、电枢回路所串起动电阻RSt阻值调到最小","B、电枢回路所串起动电阻RSt阻值调到最大","C、励磁回路所串调节电阻Rf阻值调到最大","D、RSt、Rf阻值均调到最大"]
什么是循环传送方式?