sky “天、天空”,一般用作单数.但在文学语言中,有时也用算数形式（skies）.如：
There were no clouds in the sky.天上没有云.
1、Bitter sacrifice strengtnens bold resolve .Which dares to make sun and moon shine in new skies.
为有牺牲多斗志,敢教日月换新天.（毛泽东）
2、在BRESSANONE “星夜别离"的一首诗里
I have left stars behind me 留一片星空给我的姑娘
they were disamonds in your skies 陪伴你共度孤独时光