( ( The ( conventional view ) ) ( ( is ( that ( friction ( arises ( from ( ( the irregularities ) ( in ( ( the surfaces ) ( of ( sliding objects ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ conventional) (NN view)) (VP (VBZ is) (SBAR (IN that) (S (NP (NN friction)) (VP (VBZ arises) (PP (IN from) (NP (NP (DT the) (NNS irregularities)) (PP (IN in) (NP (NP (DT the) (NNS surfaces)) (PP (IN of) (S (VP (VBG sliding) (NP (NNS objects))))))))))))) (. .)))
The conventional view is that friction arises from the irregularities in the surfaces of sliding objects.
(ROOT (S (NP (VBG Sliding) (NN friction)) (VP (VBZ is) (NP (NP (NN friction)) (SBAR (WHNP (WDT that)) (S (VP (VBZ acts) (PP (IN on) (NP (NP (NNS objects)) (SBAR (WHADVP (WRB when)) (S (NP (PRP they)) (VP (VBP are) (VP (VBG sliding) (PP (IN over) (NP (DT a) (NN surface)))))))))))))) (. .)))