狭窄场所使用Ⅱ类工具，必须装设动作电流不大于（）的漏电保护器。
A.15mA
B.30mA
C.45mA
D.75mA
参考答案：A
He has many friends at school, ________?[ ]
A. has he
B. does he
C. doesn't he
D. isn't he
温度测量仪可分为（）温度测量仪。
A、膨胀式
B、压力式
C、接触式
D、非接触式
