一光年到底有多远
        
            [yī guāng nián dào dĭ yŏu duō yuăn]
        
        
            'One light-year, how far is it?' implies a feeling of vast distance that seems almost out of reach. The light-year as a unit conveys the speaker's emotions of separation, perhaps reflecting longing for something or someone in another place, seemingly unattainable.