look up at the sky
仰望天空
the sky brightens / darkens
天空变亮/变暗
(snow) falls from the sky
雪从空中落下
a blue / grey sky
蓝天/灰色的天
the sky clears
天晴了
(clouds) drift across the sky
云层飘过天空
a clear / cloudless sky
晴朗/无云的天空
the night sky
夜空