The first indications a mariner will have of the approach of a warm front will be （）.
1、A marine sextant has the index arm set
A marine sextant has the index arm set at zero and the reflected image of the horizon forms a continuous line with the actual image. When t...
2、The lifesaving signal indicating You a
The lifesaving signal indicating You are seen - assistance will be given as soon as possible is the（）.Avertical motion of white flagsBvertical motion of a white light or flareCfiring of a green star signalDNone of the above
3、（）indicates the weight of the vessel a
（）indicates the weight of the vessel and is,therefore,according to a well known principle of physics,equal to the weight of the water it displaces.AGross tonnageBNet tonnageCDisplacement tonnageDDeadweight tonnage
4、The desirable properties of a marine f
The desirable properties of a marine fuel oil should include（）Ahigh flash point and high viscosityBlow flash point and high viscosityClow heating value and high sulphur contentDhigh heating value and low sulphur content
5、What is the first visible indication o
What is the first visible indication of the presence of a tropical cyclone or hurricane（）.AStratocumulus clouds or strange birdsBRain and increasing windsCAn exceptionally long swellDDark clouds and thebarof the storm
6、The marine diesel engine is a type of
The marine diesel engine is a type of diesel engine used on ships The （） of its operation is not very difficult to understand.AprincipleBprincipalCcauseDcase