“first day cover”的概念、定义、翻译、参考文献-科学参考

单词	first day cover
释义	first day cover Encyclopedia 工学集邮品释 first day cover首日封在新邮票发行首日，将该套邮票的全套或单枚贴在特制信封、普通信封或纪念信封的右上角，加盖当日邮政日戳或特制的首日纪念邮戳的信封。
随便看	elongated cycloid elongated egg cowry elongated epicycloid elongated hypocycloid elongated needle therapy elongated orbit elongated pyramid elongated soft palate elongated styloid process elongated tokamak elongated tortoise elongated trochoid elongate ilisha elongation elongational thickening elongational viscosity elongation at break elongation coefficient elongation factor elongation factor (EF) elongation of circumpolar stars elongation pass elongation quadric elongation rate at break of fiber elongation rate at specified load

科学参考收录了854744条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。