航空业的革新集中于民用航空喷气式发动机的研发，首先是涡轮螺旋桨发动机，后来是纯粹的喷气机。

Innovation in aviation has centered on the development of the jet engine for civil use, first in a turbo propeller form and later as a pure jet.

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飞机各种能够飞行的带翼交通工具，通常比空气重，用喷气式发动机或螺旋桨驱动。

Any of various winged vehicles capable of flight, generally heavier than air and driven by jet engines or propellers.

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应该指出，强调在这本书是关于在涡轮喷气发动机，并没有特殊的部分涉及与螺旋桨涡轮发动机。

It will be noted that the emphasis in this book is on the turbo-jet engine and that no special part deals with the propeller-turbine engine.

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