Which instrument is used to measure the relative humidity of air?（）

单项选择题（）is normally responsible for maintaining records of corrections to navigational charts and nautical publications.

A.The chief officer
B.The second officer
C.The third officer
D.The PSC officer

单项选择题The company should establish procedures by which（）receive relevant information on the safety management system in working language or language understood by them.

A.New personnel
B.The ship's personnel
C.Personnel transferred to new assignments
D.Visitor

单项选择题When two power-driven vessels are meeting head-on and there is a risk of collision,each shall（）.

A.stop her engines
B.alter course to starboard
C.sound the danger signal
D.back down

单项选择题The overall set in Malacca straight is to the NW, but from May to September there is a tendency for SE sets to prevail in some N and central parts.In this sentence,“set”refers to（）.

A.The direction of traffic flow
B.The direction of current
C.The direction of monsoon
D.The direction of wind

单项选择题（）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.

A.Gross tonnage
B.Net tonnage
C.Displacement tonnage
D.Deadweight tonnage