The red bridge over the water surface goes into the fogThe red bridge over the water surface goes into the fog
Reflection of snowy mountains in the water surfaceReflection of snowy mountains in the water surface
Reflection of the forest and mountains in the surface of the lakeReflection of the forest and mountains in the surface of the lake
В математике: граница, отделяющая геометрическое тело от внешнего пространства. Наружная сторона чего-н..