Vessel in distress（）indicate their position by any method.

The service life of distress signals must be not more than（）.

By regulation，orange smoke distress signals will expire not more than how many months from the date of manufacture?（）

Distress signal are always stored in the memory so as to start（）.

Distress signal are always stored in the memory so as to start（）.

How long must GMDSS Radio Logs be retained by the licensee when they relate to a distress situation or disaster? （）

DSC distress acknowledgements are normally transmitted by（）in respond to a receiver DSC distress call.

Sometimes lights are（）by fog，haze，dust，smoke，or precipitation which may be present at the light，or between the light and the observer，and which is possibly unknown by the observer.

All of the following are distress signals under the Rules EXCEPT（）.

All of the following are distress signals under the Rules EXCEPT（）.

All of the following are distress signals under the Rules EXCEPT（）.

The amount of fluid delivered by a positive displacement pump can be regulated by （）.