surface@@1	surface	exterior	18
surface@@1	surface	top	16
surface@@1	surface	face	14
surface@@1	surface	level	11
surface@@1	surface	cover	9
surface@@1	surface	area	8
surface@@1	surface	plane	6
surface@@1	surface	surface layer	6
surface@@1	surface	top layer	5
surface@@1	surface	layer	3