单选题All lifeboats，rescue boats，and rigid-type liferafts shall be stripped，cleaned，and thoroughly overhauled at least once every（）.A 6 monthsB yearC 18 monthsD two years

A safety feature provided on all inflatable liferafts is ______.

A.overhead safety straps

B.built in seats

C.internal releasing hooks

D.water stabilizing pockets

For the purpose of training and drills，if reasonable and practicable，rescue boats on board must be launched with their assigned crew ______．

A.once a week

B.once a month

C.once a year

D.twice a year

Written notice shall be sent to all directors, indicating all matters to be considered().

A、hereby

B、therefore

C、otherwise

D、thereafter

A SOLAS passenger ship safety certificate is required on all ______.

A.T-Boats carrying more than 49 passengers for hire

B.T-Boats that carry more than 12 passengers on an international voyage

C.T-Boats carrying more than 150 passengers for hire

D.large excursion vessels on lakes，bays，sounds，and river routes

______ 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

Licensed Patents, as used herein, ()all patents and patent applications.

A、shall mean

B、means

C、should mean

D、shall have meant