noun🔗Share信封 A paper or cardboard wrapper used to enclose small, flat items, especially letters, for mailing."My sister put the letter in an envelope and took it to the mailbox. "我妹妹把信放进信封里，然后拿到邮箱寄走了。stationerycommunicationChat with AIVocabulary GamePractice Reading
noun🔗Share信封, 封套。 Something that envelops; a wrapping."The letter was carefully placed inside the envelope. "信被小心地放进了信封里。stationerymaterialChat with AIVocabulary GamePractice Reading
noun🔗Share气囊，囊体 A bag containing the lifting gas of a balloon or airship; fabric that encloses the gas-bags of an airship."The hot air balloonist carefully inspected the envelope for any tears before filling it with hot air. "热气球飞行员在往气囊里充入热空气之前，仔细检查了囊体，看是否有任何破损。vehicleparttechnologynauticalChat with AIVocabulary GamePractice Reading
noun🔗Share包络。 A mathematical curve, surface, or higher-dimensional object that is the tangent to a given family of lines, curves, surfaces, or higher-dimensional objects."The engineer used the envelope of possible flight paths to determine the safest trajectory for the rocket. "工程师利用可能飞行路径的包络线来确定火箭最安全的轨道。mathsciencetechnicalChat with AIVocabulary GamePractice Reading
noun🔗Share包络，封包曲线 A curve that bounds another curve or set of curves, as the modulation envelope of an amplitude-modulated carrier wave in electronics."The technician carefully measured the envelope of the radio signal to ensure proper transmission. "技术员仔细测量了无线电信号的包络，以确保正确传输。electronicstechnologysignalphysicsmathChat with AIVocabulary GamePractice Reading
noun🔗Share包络，波封。 The shape of a sound, which may be controlled by a synthesizer or sampler."The musician carefully shaped the sound of the trumpet using a synthesizer to create a specific envelope. "这位音乐家使用合成器精心调整了小号的声音，以创造出特定的声音包络 (bāoluò)。musicsoundtechnologyelectronicssignalChat with AIVocabulary GamePractice Reading
noun🔗Share信封，封套。 The information used for routing a message that is transmitted with the message but not part of its contents."The envelope on the letter contained the address, but not the actual letter itself. "信封上写着地址，但信封本身并不是信的内容。technologycomputingcommunicationinternettechnicalChat with AIVocabulary GamePractice Reading
noun🔗Share信封，封套 An enclosing structure or cover, such as a membrane; a space between two membranes"The onion's outer layer is a tough envelope protecting the delicate inner parts. "洋葱的外层是一层坚韧的保护层，像信封一样包裹着里面娇嫩的部分.materialstructurestationerywritingChat with AIVocabulary GamePractice Reading
noun🔗Share性能包线，运行范围 The set of limitations within which a technological system can perform safely and effectively."The new software program has a narrow envelope of acceptable temperatures for optimal performance. "这个新软件程序的最佳性能运行范围对温度的要求很窄。technologytechnicalsystemrangeChat with AIVocabulary GamePractice Reading
noun🔗Share彗发，彗云。 The nebulous covering of the head or nucleus of a comet; a coma."The comet's envelope was a bright, fuzzy cloud of gas and dust. "这颗彗星的彗发是一个明亮、模糊的气体和尘埃云。astronomyspaceChat with AIVocabulary GamePractice Reading
noun🔗Share护堤，堤墙 An earthwork in the form of a single parapet or a small rampart, sometimes raised in the ditch and sometimes beyond it."The soldiers built an envelope around the village to protect it from enemy attack. "士兵们在村庄周围修筑了一道护堤，用以保护它免受敌人的袭击。militaryarchitectureChat with AIVocabulary GamePractice Reading
verb🔗Share包裹，覆盖。 To surround or enclose."The thick cardboard box enveloped the fragile glassware, protecting it from damage during shipping. "厚实的纸板箱包裹着易碎的玻璃器皿，保护它在运输过程中免受损坏.areaenvironmentChat with AIVocabulary GamePractice Reading
