morning dew and evening mist; a description of changing natural scenery

山谷中终日缭绕着朝露暮霭，景象如梦似幻。

short-lived or transient; impermanent like the morning dew and evening mist

人生苦短，犹如朝露暮霭，我们应当珍惜眼前的每一刻。