A、 If a power supply system is independent to provide service to only one component or single- function system,it will be discussed together with the components or systems it serves.
B、 When a power source services a singlecomponent,or serves a single functioning system,that power source will be included in the discussion of the component or system which it serves.
C、 When a power supply is a complete component or single-function system,the device it serves is discussed separately from its own component or system.
答案：B
A、 If a power supply system is independent to provide service to only one component or single- function system,it will be discussed together with the components or systems it serves.
B、 When a power source services a singlecomponent,or serves a single functioning system,that power source will be included in the discussion of the component or system which it serves.
C、 When a power supply is a complete component or single-function system,the device it serves is discussed separately from its own component or system.
答案：B
A. If an AC circuit consists of resistance only,the value of the impedance is the same as the resistance.
B. If an AC circuit consists of impedance only,the value of the capacitance is the same as the impedance.
C. If an DC circuit has capacitance only,the value of the resistance is the same as the capacitance.
A. 显示连接点位置、转弯半径等信息的系统原理图应包含在内。
B. 显示连接点位置、转弯半径等信息的图示应包含在内。
C. 显示连接点位置、转弯半径等信息的功能图应包含在内。
A. 文件必须经常修订。
B. 文件必须易于修订。
C. 文件必须容易阅读和看见。
A. 停在地面时,在液压系统没有增压的情况下,方向舵的正常位置是低垂位到伺服控制止挡。
B. 在地面模式,在液压系统没有增压的情况下,方向舵的正常位置是向下偏转到伺服控制止动位。
C. 在地面时,在液压系统增压的情况下,方向舵的正常位置是向下偏转到伺服控制止动位。
D. B.在地面模式,在液压系统没有增压的情况下,方向舵的正常位置是向下偏转到伺服控制止动位。
E. C.在地面时,在液压系统增压的情况下,方向舵的正常位置是向下偏转到伺服控制止动位。
A. The housing for the voice recorder unit has these properties: water tolerance,shock resistant and heat resistant.
B. The container for the voice recorder unit has these properties: watertproof,spin resistant and heat resistant.
C. The container for the voice recorder unit has these properties: watertight,shock resistant and heat resistant.
A. Some jobs or processes consist of several basic operations,with a number of minor steps or work items under each.
B. Some basic operations with a few small steps or work items are included in some work or processes.
C. Some jobs or processes constitute a few basic operations,with several minor steps or work items under each.
A. 刮痕的最大长度为 5 英寸。
B. 裂缝的最大长度为 5 英寸。
C. 刮痕的最大长度为 5 英尺。
A. Oxygen occurs occasionally.
B. Oxidation occurs very easily.
C. Oxygen happens very easily.
A. 给机械工分配不同的维修任务。
B. 给工程人员分配不同的操作任务。
C. 给技术人员分配不同的维修任务。
A. These buses consume power directly from the battery.
B. These buses accept the direct current of battery.
C. The battery supplies power directly to these buses.
