( Viruses ( ( cause ( ( most cases ) ( of ( colds ( and ( respiratory flu ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Viruses)) (VP (VBP cause) (NP (NP (JJS most) (NNS cases)) (PP (IN of) (NP (NNS colds) (CC and) (NN respiratory) (NN flu))))) (. .)))
Viruses cause most cases of colds and respiratory flu.
(ROOT (S (NP (NP (DT The) (JJ common) (NN cold)) (CC and) (NP (NN flu))) (VP (VBP are) (NP (NP (NNS examples)) (PP (IN of) (NP (NP (JJ human) (NNS diseases)) (VP (VBN caused) (PP (IN by) (NP (NNS viruses)))))))) (. .)))