( ( When ( light ( falls ( on ( an ( unpolished ( ( -LRB- ( diffuse -RRB- ) ) surface ) ) ) ) ) ) ) ( , ( ( light waves ) ( ( are ( reflected ( in ( ( all directions ) ( because ( of ( the ( overall ( even surface ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NN light)) (VP (VBZ falls) (PP (IN on) (NP (DT an) (JJ unpolished) (PRN (-LRB- -LRB-) (NP (NN diffuse)) (-RRB- -RRB-)) (NN surface)))))) (, ,) (NP (JJ light) (NNS waves)) (VP (VBP are) (VP (VBN reflected) (PP (IN in) (NP (NP (DT all) (NNS directions)) (PP (RB because) (IN of) (NP (DT the) (JJ overall) (JJ even) (NN surface))))))) (. .)))
When light falls on an unpolished (diffuse) surface, light waves are reflected in all directions because of the overall even surface.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NN light)) (VP (VBZ reflects) (PP (IN from) (NP (DT a) (JJ rough) (NN surface)))))) (, ,) (NP (PRP it)) (VP (VBZ gets) (ADJP (JJ diffused))) (. .)))