415.When the selector is in the 100% position, the user will( ) pure oxygen ( )

522.It has a single shaft and operates at a constant speed ( )

521.为避免污染,必须在非常清洁的环境里执行该任务。 ( )

520.在某些情况下,尤其是对于复杂的飞机,可能需要针对飞机及其系统的适当维修提供专门培训。( )

519.Some airplanes , particularly relatively simple airplanes , may not need CAPs because adequate information to maintain their continuing airworthiness throughout their useful lives is contained in the airplane＇s maintenance manual ( )

518.通气油箱排放单向活门是在 1 号和 2 号主油箱外侧油箱端部肋上。 ( )

517.你有权免费复制或出版本文件或其任何后续修改或修订的全部或部分内容。 ( )

516.你可以调节音量控制。( )

515.Make sure that equipment in the area is cleared ( )

514.WHEN YOU PUSH THE AGENT PUSHBUTTON,THE FIRE EXTINGUISHER CARTRIDGE[ ]( )

513.警告,告诫,注意可以用于来突出强调关键点( )