单选题All fog signals shall be sounded every two minutes with the exception of a vessel（）.A underway or making wayB under sail or under towC anchored or agroundD not under command or restricted in her ability to maneuver

A vessel on the high seas that is not under command shall display which of the following day signals? ______

A.Two black balls

B.Three black balls

C.Two red balls

D.Three red balls

Concerning the identification signal for a pilot vessel, in fog, which statement is TRUE?___.

A.When at anchor, the pilot vessel is only required to sound anchor signals

B.The identification signal must be sounded any time the pilot vessel is underway

C.The pilot vessel may only sound the identity signal when making way

D.All of the above

______ of the following statements is（are）correct regarding motor lifeboats on cargo vessels．① The motor of each lifeboat shall be operated in the ahead and astern position for a period of not more than 5 minutes once in each week；② The fuel tank of all motor-propelled lifeboats shall be emptied and the fuel changed at least once in every year．

A.① only

B.② only

C.Both ① and ②

D.Neither ① nor ②

All the crewmembers shall be at the station as required by the muster list when in firefighting drill______minutes after hearing the alarm，and the duty engineer shall be able to make the fire pumps available with______minutes．

A.2/5

B.2/3

C.3/2

D.2/2

If practical, when shall a manned vessel being towed sound her fog signal?______.

A.Immediately before the towing vessel sounds hers

B.Immediately after the towing vessel sounds hers.

C.As close to the mid-cycle of the towing vessel’s signals as possible

D.At any time as long as the interval is correct

材料：

Condor a catamaran vessel operating between the Channel Islands and France．The vessel has two main engines in each hull．All propulsion units are duplicated，with each set independent from the other．

Shortly after leaving St Helier，Jersey，with 31 passengers and 18 crew，the fire alarm sounded indicating a fire in the starboard engine room．This was confirmed by the closed circuit television surveillance system which showed flames in the vicinity of the starboard outer main engine．The vessel was immediately stopped，all machinery in the starboard engine room was stopped and the fuel supplies shut down．Jersey Radio was informed of the situation two minutes after the alarm sounded. After closing all ventilation openings and accounting for all personnel，halon fire smothering gas was released into the starboard engine room．This was done five minutes after the fire alarm first sounded. The crew maintained boundary cooling and intermittently operated the sprinkler system to the affected space．

Twenty minutes after the alarm sounded the situation was considered to be under control．Using the port main engines the vessel returned to St Helier where assistance was available from shore based emergency services．

问题：

Condor has two ________ main engines．

A.combined

B.independent

C.couple

D.double

The fire accident happened in ________．A.both the engine rooms

B.neither engine rooms

C.the port engine room

D.the starboard engine room

The fire was mainly extinguished with ________．A.water

B.chemical agent

C.foam

D.powder

It can be concluded that ________．A.no officials from any authority know the accident after it happened

B.some officials ashore must have learnt the accident at very beginning

C.there must be casualties even they were not mentioned in the report

D.fire is not dangerous on board vessel

请帮忙给出每个问题的正确答案和分析，谢谢！