国际遇险呼救频率
International distress frequency
国际遇险呼救电码
international distress code
国际遇险频率
International distress frequency
Antislip
Anodizing determintion of second derivative
国际遇险频率国际遇险呼叫频率
International distress frequency
国际遇险频率国际遇险频率
International distress frequency
无线电话遇险频率
radiotelephone distress frequency
国际遇险呼叫频率
International distress frequency
海上遇险频道
maritime distress channel
海上搜救频率
Frequencies Used for Search and Rescue at Sea
搜救频率
search and rescue frequency