1·The chemical composition of rainfall changes slightly as rain clouds move.
降雨的化学成分随着雨云的移动而发生轻微变化。
2·Rain clouds come to play again.
雨云再度前来嬉戏。
3·I see rain clouds are gathering.
我看见天空正乌云密布。
4·Send us rain clouds, Grandfather.
爷爷，求您给我们送来雨云吧！
5·Rain clouds are banking up.
雨云正在聚积起来。
6·Rain clouds in the sky.
天上有朵朵乌云。
7·Janet watched the rain clouds darken the sky.
珍妮特看着乌云将天空变暗。
8·Do you think those are rain clouds on the horizon?
你认为天边的那些云彩是雨云吗？
9·They hastened the pace when they saw rain clouds .
他们看见乌云便加快了脚步。
10·Dark rain clouds were coming over so he went home to find his Mum.
乌云来了，索尼尔只好回家去找妈妈。