( It ( ( is ( ( ( the ( high ( surface tension ) ) ) ( of water ) ) ( that ( allows ( ( some insects ) ( to ( `` ( ( walk '' ) ( on water ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (NP (NP (DT the) (JJ high) (NN surface) (NN tension)) (PP (IN of) (NP (NN water))) (SBAR (WHNP (WDT that)) (S (VP (VBZ allows) (S (NP (DT some) (NNS insects)) (VP (TO to) (VP (`` ``) (VB walk) ('' '') (PP (IN on) (NP (NN water))))))))))) (. .)))
It is the high surface tension of water that allows some insects to &quot;walk&quot; on water.
(ROOT (S (NP (JJ Surface) (NN tension)) (VP (VBZ is) (ADJP (JJ responsible) (PP (IN for) (NP (DT the) (NN fact)))) (SBAR (IN that) (S (NP (JJ small) (NNS insects)) (VP (MD can) (VP (VB walk) (PP (IN on) (NP (NN water)))))))) (. .)))