第1题：
The boom stops are installed on an offshore crane to ______.
A.prevent the boom from being raised too high
B.prevent the boom from swinging
C.support the boom when not in use
D.prevent the boom from being lowered
第2题：
With a given load on the cargo hook，the thrust on a cargo boom ______.
A.increases as the angle to the horizontal increases
B.increases as the angle to the horizontal decreases
C.is greatest at an angle of 45° and decreases as the boom is raised or lowered
D.is least at an angle of 45° and increases as the boom is raised or lowered
第3题：
On a crane, the boom indicator tells the operator what angle the boom angle is compared to the ______.
A.vertical position
B.horizontal position
C.boom stop angle
D.minimum radius angle
第4题：
A boom vang ______.
A.holds the boom down and flattens the main sail
B.draws the head of the sail to windward
C.tautens the standing rigging
D.douses the gaff topsail
第5题：
The boom indicator on a crane will indicate the ______．
A.Length of the boom
B.Angle of the boom
C.Lifting capacity of the boom
D.Direction of the boom
第6题：
With a given load on the cargo hook，tension in a single span topping lift ______.
A.increases as the boom's angle to the horizontal increases
B.is at a maximum when the boom is at a 45° angle to the horizontal
C.increases as the boom's angle to the horizontal decreases
D.decreases as the boom's angle to the horizontal decreases
第7题：
The boom stops on a pedestal crane prevent the boom from ______.
A.being raised too high
B.swinging at sea
C.overloading when not in use
D.being lowered too low
第8题：
此题为判断题(对，错)。
第9题：
What is meant by the term“luffing the boom”of a crane ________．
A.Stopping the boom
B.Topping or lowering the boom
C.Moving the boom left or right
D.All of the above
第10题：
日本旅游业为什么能够迅速发展？