能全部通过七号筛,但混有能通过九号筛不超过95%的粉末()
A.最粗粉
B.粗粉
C.细粉
D.最细粉
E.极细粉
参考答案:E
—Is there _____ wrong with me, doctor?
—I'm afraid so. Your heart is beating a bit too slow. [ ]
A.something
B.anything
C.everything
D.nothing
三相笼型异步电动机的电气控制线路,如果使用热继电器作过载保护,就不必再装设熔断器作短路保护。