prevalence rate

incidence rate

With the price of oil (goes up), the economy of (oil-producing) countries is (expanding) (at a high rate).

A:goes up B:oil-producing C:expanding D:at a high rate

When determining the freight rate, the age-old principle of "what the traffic can bear" is increasingly substituted by the( )principle nowadays．

A:open market rate B:surcharges C:selwice cost D:stowage factor

class rate

When determining the freight rate, the age-old principles of “what the traffic can bear” is increasingly substituted by the ( )principle nowadays.

A:open market rate B:surcharges C:service cost D:stowage factor

When should operational check on navigation equipment be done?

A:Regulary, when preparing for seaand entering port B:As often as possible C:When errors are indicated D:When time allows

"In traditional navigation ______ were used for indication of the ships course．

A:degrees on the full scale of 0~360 B:cardinals and points C:deviations D:port and starboard"

Red sectors of navigation lights warn mariners of________．

A:floating debris B:heavily trafficked areas C:recently sunken vessels D:shoals or nearby land"