一光年的距离大得令人难以想象。 The distance of a light year boggles the imagination.
1光年是以每秒186000英里的速度走过一年的距离，约为6万亿英里。 A light year is the distance which light travels at186,000 miles per second in one year, namely6 million million miles.
天津四，天鹅α星在天鹅座最亮的一颗恒星，距地球大约有1，630光年 The brightest star in the constellation Cygnus, approximately1,630 light-years from Earth.
北河二双子座中的一颗双星，是这组星中最明亮的一颗，距地球约46光年 A double star in the constellation Gemini, the brightest star in the group, approximately46 light-years from Earth.
