夜幕降临,我们开始往家走。
night falling, the children hurried home.夜色降临,孩子们急忙回家。
In overcast conditions the skylight is always blue (clear skies are needed for the pink light) and it is generally much darker, with night falling much more quickly.在阴天,天光总是蓝色的(只有晴天有粉红色光),而且通常更深,夜晚也来得更快。