( ( ( The ( river Main ) ) ( in ( its ( natural state ) ) ) ) ( ( is ( ( a ( fast-moving ( stream unsuitable ) ) ) ( for shipping ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN river) (NN Main)) (PP (IN in) (NP (PRP$ its) (JJ natural) (NN state)))) (VP (VBZ is) (NP (NP (DT a) (JJ fast-moving) (NN stream) (NN unsuitable)) (PP (IN for) (NP (NN shipping))))) (. .)))
The river Main in its natural state is a fast-moving stream unsuitable for shipping.
(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.