envelope

envelopes and stamps.信封和邮票

She tore open the envelope and frantically read the letter..她撕开信封慌忙看信。

He got a job stuffing envelopes (= filling them with letters ) at the campaign headquarters..他找了一份在竞选总部装信封的工作。

flight envelope,飞行包线

nuclear envelope,核膜；核被膜

envelope curve,包络曲线；包迹

failure envelope,断裂点轨迹；破坏包络线

push the envelope,挑战极限；接近甚至超越安全限度；越过底线

glass envelope,玻璃封装；玻壳