單項(xiàng)選擇題A backlash below a lock is defined as（）.

A.a current setting your vessel on the wall
B.a current setting into the lock chamber
C.an eddy working along the lower guide wall
D.a current setting counterclockwise


您可能感興趣的試卷

你可能感興趣的試題

1.單項(xiàng)選擇題The apparent wind’s speed can be zero only when two conditions are present. One condition is that the true wind（）.

A.must be from dead ahead
B.speed must be zero
C.must be from dead astern
D.must be on the beam

2.單項(xiàng)選擇題In the Northern Hemisphere you are caught in the dangerous semicircle with plenty of sea room available. The best course of action is to bring the wind on the（）.

A.starboard bow and make as much headway as possible
B.starboard quarter，and make as much headway as possible
C.port quarter，and make as much headway as possible
D.port bow，and make as much headway as possible

3.單項(xiàng)選擇題The cold ocean current which meets the warm Gulf Stream between latitudes 40°and 43°N to form the cold wall is called the（）.

A.North Cape Current
B.Labrador Current
C.Greenland Current
D.North Atlantic Current

5.單項(xiàng)選擇題The currents are（）mosoonal origin．

A.from
B.on
C.in
D.of

6.單項(xiàng)選擇題In the Northern Hemisphere，a wind that shifts counterclockwise is a（）.

A.veering wind
B.backing wind
C.reverse wind
D.chinook wind

7.單項(xiàng)選擇題Ocean currents are well defined and（）.

A.create large waves in the direction of the current
B.change direction 360°during a 24 hour period
C.remain fairly constant in direction and velocity throughout the year
D.are characterized by a light green color

9.單項(xiàng)選擇題In the Northern Hemisphere the major ocean currents tend to flow（）.

A.clockwise around the North Atlantic and North Pacific Oceans
B.clockwise or counterclockwise depending on whether it is warm or cold current
C.counterclockwise except in the Gulf Stream
D.counterclockwise around the North Atlantic and North Pacific Oceans