light year The distance travelled by light in 1 year. A light year is approximately 9.46×1012 km. Because of the vast distances in space, the light year is the basic unit of distance in astronomy.
light year
数学辞典收录了4151条数学词条，基本涵盖了常用数学知识及数学英语单词词组的翻译及用法，是数学学习的有利工具。