“平常信函”的概念、定义、翻译、参考文献-科学参考

单词	平常信函
释义	平常信函 Encyclopedia 工学信函释 ordinary letter平常信函信函的一种常见形式。邮政企业在收寄时不出具收据，处理时不登记，投递时不要求收件人签收，不接受用户查询。简称平信。
随便看	spherical convergent flap nozzle spherical convexity spherical coordinate spherical coordinates system spherical coordinate system spherical covering spherical CR structure spherical cuboctahedron spherical curvature spherical curve spherical cyclic curve spherical defect spherical deflection analyzer spherical deformation tensor spherical degree spherical density spherical derivative spherical design spherical digon spherical distance spherical distribution spherical domain spherical earth theory spherical element spherical equilateral triangle

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。