A.To ensure that interference to proprietary communications is minimized
B.To ensure that only voice communications can be effected on the distress frequency or channel
C.To ensure that a distressed vessel will have a "window" twice each hour for transmitting routine messages
D.To ensure that interference on a particular frequency or channel to communications concerning emergency traffic is minimized

A.1492 kHz
B.1892 kHz
C.2082 kHz
D.2182 kHz

A.Red flares or red rockets
B.Continuous sounding of fog signaling apparatus
C.International Code Flags "November" and "Charlie"
D.Basket hanging in the rigging

A.Stations not directly involved with the on-going distress communications may not transmit on the distress frequency or channel
B.Stations remaining off the air to safeguard proprietary information
C.Two three-minute silent periods，at 15 and 45 minutes after the hour，that provide a transmitting "window" for distressed vessels to transmit distress alerts using J3E
D.Communications on a distress frequency or channel is banned for 24 hours following the cessation of the distress traffic

A.Distress and alarm signals transmitted or intercepted
B.Times of beginning and end of watch period
C.Routine navigational traffic
D.Daily statement about the condition of the required radiotelephone equipment