单项选择题
A.2s和30HzB.0.125s和30HzC.0.125s和13HzD.2s和13Hz
A.0.01~100HzB.0.01~1000HzC.0.05~100HzD.0.05~1000Hz
A.0.01~100HzB.0.01~1000HzC.100~500HzD.100~1000Hz