Natural landscape with the reflection of a tree on the water surfaceNatural landscape with the reflection of a tree on the water surface
Where is the water surface, and where is the sky, everything has mergedWhere is the water surface, and where is the sky, everything has merged
В математике: граница, отделяющая геометрическое тело от внешнего пространства. Наружная сторона чего-н..