安全谜语猜猜看:安全规章天天讲（安全用语）--（）
参考答案：警钟长鸣
--- He went to see the man who was in hospital yesterday. --- ____________.
A．So did we
B．So we did
C．We did so
D．Did so we
无线电导航机载接收机的作用是通过接收并处理（）来获取导航参量。
A.无线电波的电参量
B.无线电波的传播路径
C.无线电波的传播媒质
D.无线电波的传播速度
