A.to ventilate the holdB.to separate the cargoC.to repl……

单项选择题When two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision,they shall be deemed to be in（）.

A.head-on situation
B.crossing situation
C.overtaking situation
D.close-quarters situation

单项选择题Chart Publication correction record Card system ensures that every chart is properly corrected（）.

A.in use
B.prior to use
C.after use
D.When chart received on board

单项选择题What is the distance from the bottom of a wave trough to the top of a wave crest?（）

A.Wave length
B.Wave height
C.Wave breadth
D.wave depth

单项选择题Depths in the routes (Malacca and Singapore Straits) vary between 20m and about 23m but there are many areas of sand waves and depths are liable to change. The statement infers that（）.

A.depths in Malacca and Singapore Straits are stable
B.depths in Malacca and Singapore Straits are changeable
C.depths in Malacca and Singapore Straits are invariable
D.depths in Malacca and Singapore Straits are the same all the time

单项选择题The lifeboat is constructed of（）

A.totally enclosed
B.glass-reinforced plastic
C.self-righting
D.powered