503 、 The two most common types of engines used in helicopters are the reciprocating engine and the turbine engine.

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. 　用密封剂填充补片及相邻结构之间的缝隙。

B. 　用密封剂填充补片的缝隙,并粘接相邻结构。

C. 　在附近的密封结构和补片之间留出空隙。

A. 　STE 是一种活的语言,需要用户的反馈来不断改进。

B. 　STE 是一种生活的语言,需要用户的培育来不断验证。

C. 　STE 是一种活的语言,需要用户的输入来不断应用。

A. 　 With the aid of the component manufacturer, all components in this chapter can be overhauled in any
workshops with different qualifications.

B. 　 Without the data supplied by the component manufacturer, it is possible for the most qualified shop to
overhaul any components included in this chapter.

C. 　 You must overhaul any of all components in this chapter in an eligible shop on the basis of data provided
by the component manufacturer.

A. 　找到中点,然后将测量出的数据除以 2。

B. 　为找到中点;将测量出的间隙除以 2。

C. 　找到中点,用 2 除以测量出的间隙。

A. 　所有三个螺栓孔必须与燃油管匹配。

B. 　所有三个支架孔必须与燃油管对齐。

C. 　所有三个支架孔必须与然油管齐平。

A. 　删除某些规则,并将其概念包含在其他规则中。

B. 　删除某些规则,并将其细则包含在其他规则中。

C. 　删除某些尺寸,并将其概念包含在其他尺寸中。

A. 　1944 年,随着空中航行法令和规章的各种要求得以实现,英国民用适航机构形成了适航标准的法典

B. 　1944 年,英国制定了民用适航要求来形成空中航行指令和规则守则。

C. 　1944 年,随着英国民用适航要求的制定,形成了适航标准的法典,通过该法典,空中航行法令和规章的
各种要求得以实现。

A. 　 Each Chapter or Section is to begin with a specific instruction of the system and its Operation and should
be labeled "Description and Operation"

B. 　 A general description of the system begins with each Chapter or Section and its operation and should be
labeled "Description and Operation"

C. 　 Each Chapter or Section is to start with a general description of the system and its operation and should
be labeled" Description and Operation".

A. 　 Retract the ram air turbine manually.

B. 　 A The ram air turbine can be pushed to the retracted position manually.

C. 　 Push the ram air turbine with your hands in the direction that the turbine retracted.