词汇与结构An oxygen system is ________ but only for emergency use and only intended to allow time to descend to a safe altitude.
A. restrained
B. retained
C. reserved
D. restricted
查看答案
词汇与结构Cabin altitude is not normally______ at ground level (0ft) pressure throughout the flight because doing so stresses the fuselage and uses more fuel.
A. maintained
B. declared
C. claimed
D. remained
词汇与结构_______ is achieved by the design of an airtight fuselage engineered to be pressurized, a source of compressed air and an environmental control system (ECS).
A. Pressurization
B. Compression
C. Decompression
D. Pressure
词汇与结构The most common source of compressed air for pressurization is bleed air ______ from the compressor stage of a gas turbine or turboprop propulsion engine, usually the second or third last compressor ring.
A. distracted
B. extended
C. extracted
D. distracting
词汇与结构Typically, compressed air is bled from at least two propulsion engines each system being fully ________.
A. filled
B. extra
C. refilled
D. redundant