【单选题】
Echo sounder sends a（） (无线电信号)from the bottom of the ship to the seabed.
A、radio signal
B、radio wave
C、signal
D、signal radio
查看正确答案A、echo sounder B、instrument C、echo sounding D、sound signal
搜题
更多“Echo sounder sends a（） (无线电信号)from the bottom of the ship to the seabed.”相关的问题
第9题
A、actual depth of water B、actual depth of water below keel C、average depth from waterline to hard bottom D、average depth of water to soft bottom
