( ( Jet stream ) ( ( ( go stream ) now ) . ) )
(ROOT (S (NP (NNP Jet) (NN stream)) (VP (VBP go) (NP (NN stream)) (ADVP (RB now))) (. .)))
Jet stream go stream now.
(ROOT (S (NP (NNP Jet) (NNP streams)) (VP (VBP are) (ADVP (RB fast)) (VP (VBG moving) (NP (NP (NNS rivers)) (PP (IN of) (NP (NN air))) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (VP (VBG going) (PP (IN in) (NP (NP (JJ opposite) (NNS directions)) (VP (VBN called))))))))))) (. .)))
Jet streams are fast moving rivers of air that are going in opposite directions called.