可编程序控制器（）模块用来接收和采集现场设备的输入信号
A、通讯
B、CPU
C、输出
D、输入
参考答案：D
—He used to be quiet, didn't he?
—______ And he still enjoys keeping quiet! [ ]
A. No, he didn't.
B. Yes, he did
C. Never.
D. I am not sure.
散装蓖麻籽属于《BC规则》中具有化学危险性固体散装货物的第（）类。
A．6.1
B．9
C．8
D．4.1
