Envelope velocity
[电] 波封速度
🧩 词语组成解析
envelope
['envələʊp]
n. 信封，封皮;壳层，外壳;包裹物;[生物学]膜，包袋;
en 表示\"进入…之中，包围\" +velop =cover（盖上） +e → .信封, 封套, 封袋, [天]包层, [数]包迹, [生]包膜
🗣️ 情景例句
Did you know I can type almost 60 words per minuter?
你知道吗，我能每分钟打60个字。
Coming events cast their shadows before them.
山雨欲来风满楼。
He goes home early everyday for fear that his wife would be angry.
他每天很早就回家，免得老婆生气。