80、The fuel vent system keeps the pressure of the fuel tanks near the ambient pressure. Too large a pressure
difference can cause damage to the wing structure.

A. 　 In some cases, for complex aircraft, special training should be conducted so that the aircraft and its
systems can be maintained properly.

B. 　 Sometimes,especially for complex airplanes, it may be necessary to provide specific training in the proper
maintenance of then airplane and its systems.

C. 　 Sometimes, for particularly complex airplanes, it is required to provide specia1 training so as to perform
proper maintenance of the aircraft and its systems.

A. 　本节必须规定型号合格证所要求的每次强制更换时间,结构检查间隔,以及相关的结构检查程序

B. 　本节必须规定每一次强制更换时间,结构检查间隔,和机型证书所要求的相关的结构检查程序

C. 　本节必须规定部件更换的时间,结构检查时间,和相关的结构检查程序所需的型号合格证

A. 　保留勤务部件,更换那些损坏的

B. 　报废损坏的部件后,保留所有可用的。

C. 　保留所有可用的部件,报废那些损坏的。

A. 　如果故障频繁出现,进行系统测试。

B. 　如果故障定期出现进行系统测试。

C. 　如果故障随机出现,进行操作测试。

A. 　 station shows the height along the fuselage between the reference datum and the position

B. 　 station is the distance of a point of fuselage to the location of reference datum along the

C. 　 station means a position along the fuselage measured in inches from the reference datum

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.

A. 　 The airworthiness section may recommend each expected replacement time.

B. 　 The replacement time must be set forth in part of airworthiness section

C. 　 Airworthiness section must set forth each mandatory replacement time.

A. 　 Keep out of the engine before it starts.

B. 　 Keep away from the intake area before the engine starts
in flight, at the lowest speed that will ensure correct engine

C. 　 Go away from the exhaust area before the engine starts.

A. 　变更表格的发起者通常会得到 STEMG 评估和决定的相关通知。

B. 　变更表格的发起人通常需要告知大家相关的 STEMG 评估和决定。

C. 　变更表格的组织通常被告知相关的 STEMG 条款和决定。

A. 　 A brush is cleaned by the filter element.

B. 　 The filter element and a brush are clean.

C. 　 Use a brush to clean the filter element.