转子位置检测器实际就是检测转子上磁极位置的传感器，只要把它安装在电动机转轴上便会发出信号，控制晶闸管通断。
参考答案：错
男性，60岁，心前区阵发性疼痛1个月，多在夜间发作，与活动无关。每次发作15分钟，发作时心电图Ⅱ、Ⅲ、aVF导联ST段抬高。首选治疗的药物是
A．硝酸酯类
B．β受体阻断剂
C．钙离子通道阻断剂
D．洋地黄类
E．乙胺碘呋酮
—Our P.E. teacher isn't as young as he _____, is he?
—No, but he is one of _____ in our school.[ ]
A. looked; the youngest teacher
B. looks; the youngest teachers
C. looks; the oldest teachers
D. looked; the oldest teacher
