“第二范畴集”概念、定义、翻译-科学时代

单词	第二范畴集
释义	数学词汇手册第二范畴集 set of the second category
随便看	direct observation direct observation direct occurrence of description direct octaves direct operating expenses direct optical viewfinder director director director director director director director director director director director director director director and officer liability insurance director and officer liability insurance (D&O liability insurance) directorate direct orbit director board director circle

科学时代收录了1160609条科普词条，基本涵盖了常见科普常识及英语词汇的翻译，是科学学习和研究的有利工具。