typical contract like this last many many years,
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送交者: steven 于 2009-04-06, 15:44:46:
回答: they won't last to 2070 由 meiyou 于 2009-04-06, 15:37:08:
in fact, non of these are one time deal. Parts, upgrade and many other things will still in production to ensure the airplanes' combat readiness. B-52 was first made in 1955, and still in use.
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