“空集”概念、定义、翻译-科学时代

单词	空集
释义	数学词汇手册空集 empty set；null set；void set
随便看	upward irrigation upward-looking eyes upward mining upward mobility upward mobility upward movement upward pulling rigidity upward revaluation of currency upward slope upward stretching upward stroke upward swing upward terrestrial radiation upward total radiation upward vortex in cyclone upward welding upwarping upwash upwave upwelling upwelling upwelling upwelling upwelling area upwelling area

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。