Passage through the Suez Canal is operated on a （） system．

A.the vessel
B.shall not vessel
C.the vessel should
D.should vessel

A.light，variable winds with little or no humidity
B.strong，gusty winds that blow from the same general direction all year
C.steady winds that reverse direction semiannually
D.strong，cyclonic winds that change direction to conform to the passage of an extreme low pressure system

A.straight
B.direct
C.forward
D.on