GL系列感应式过电流继电器主要包括电磁元件等（）元件
A.一个
B.两个
C.三个
D.四个
参考答案：D
The teacher asked the girl again, raising his voice a bit, but still _____ no answer.
A. receiving
B. received
C. receive
D. to receive
在工程技术中，通常用电感式传感器测量（）。
A.电压
B.位移
C.速度
D.磁场强度
