関連ワード:  morse code 3 short 3 long 3 short    morse code 3 short    morse code 3 short 1 long    morse code 3 short 2 long    morse code 3 short one long    morse code 3 short beeps    morse code 3 long 2 short meaning    morse code 3 long 4 short    morse code 3 short 2 short    shorter signal in morse code 3 letters