391. Grease the fasteners

A. 对2号引擎进行排故。

B. 对2号发动机进行大修。

C. 对2号发动机进行校验。

A. 如果此说明书被用于准备一份持续适航程序,目的是被适航当局FAA认可,那么可能需要更改为合适的机构和规章;

B. 如果此说明书被用于准备一份持续适航程序,目的是被适航当局,比如FAA认可,那么可能需要更改为合适的机构和规章;

C. 如果此说明书被用于准备一份持续适航程序,目的是被FAA以外的适航当局认可,那么可能需要更改为合适的机构和规章;

A. The electronic signature system shall be controlled severely and ensue the identity of the signature, signature security, unchangeable and retrospective by identification and authentication of the signatory validity;

B. The electronic signature system shall be controlled strictly and ensue the identity of the signature, signature security, revisability and traceability by identification and authentication of the signatory validity;

C. The electronic signature system shall ensue the identity of the signature, signature security, undeniable and retrospective by identification and authentication of the signatory validity. It should be controlled strictly;

A. 如果部件跌落,有可能会造成轻微的损坏。

B. 如果部件掉落,可能会造成永久性的损坏。

C. 部件永久性的损坏可能是由掉落造成的。

A. The captain＇s primary flight, navigation, and center lower engine display units must be cleaned since the ventilation holes behind them are clogged by lint, dust and debris.

B. Clean the vent holes behind the captain＇s primary flight navigation and lower middle engine display units which are blocked by lint, dust and debris.

C. Clean all lint, dust and debris from the ventilation holes located on the aft side of the captain＇s primary flight navigation, and center lower engine display units.

A. 测试的部分作用是给出工作的方向。

B. 工作的部分作用是用于测试方向。

C. 本部分测试的目的是为工作提供指导。

A. Check wash basin drains, water tap and its lines for leakage.

B. Inspect the washing sink, faucet and its pipe for leakage.

C. Examine the washing hand drain port,tap and the line for crack.

A. That portion of the system and its controls which supply cooled air to the cabin. Includes items such as the cooling unit, indicating systems related to the cooler operation, etc., as applicable. Does not include temperature control and indicating systems.

B. That portion of the system and its controls which supply cooled air to the cabin. Includes items such as the cold unit, indicate systems related to the cooling operation, etc., as applicable. Does not include temperature control and indicating systems.

C. That portion of the system and its controls which supply cooled air to the cockpit. Includes items such as the cooler unit, indicating systems related to the cooler operation, etc., as applicable. Does not include hot control and indicating systems

A. A visible signal is used in aural warning device when a problem occurs.

B. A signal both can be heard and seen is used in the Aural warning device.

C. Aural warning device emits a signal that can be heard to represent a problem.

A. The smoke sensor in each detector monitors when the smoke density is above a previous limit. If the density keeps higher than the limit for about eight seconds, the sensor set the detector to the alarm condition.

B. The smoke sensor in each detector monitors for smoke density above a preset limit. If the density stays above the limit for appropriately eight seconds, the sensor sets the detector to the alarm condition.

C. The smoke transducer monitors for smoke density above a presumed limit of each detector. If the density remains over the limit about eight seconds, the transducer turn the detector to the alarm condition.