_____ of the controllable pitch propeller enables the blades to be moved to change the pitch angle
An external mechanism
B. An internal mechanism
C. An interlock device
D. A hunting gear system
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what is IMO ？what is ISO 9000？what is ISM ？what is SMS system ？
为了对抗衰退，美联储可以________。
A. 通过购买有价证券来降低联邦基金率
B. 通过卖出有价证券来降低联邦基金率
C. 通过购买有价证券来提高联邦基金率
D. 通过卖出有价证券来提高联邦基金率
E. 降低利息收入的收入税率
After the SSP being checked by a duly authorized officials of a port State, whom should be
A. Port State
B. Flag state
C. The CSO
D. The Administration
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