( ( A watershed ) ( ( is ( ( ( an area ) ( of ( land ( between ( mountain ( ridge lines ) ) ) ) ) ) ( ( in which ) ( ( all water ) ( drains ( into ( a ( common ( stream ( or ( river system ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN watershed)) (VP (VBZ is) (NP (NP (DT an) (NN area)) (PP (IN of) (NP (NP (NN land)) (PP (IN between) (NP (NN mountain) (NN ridge) (NNS lines))))) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (DT all) (NN water)) (VP (VBZ drains) (PP (IN into) (NP (DT a) (JJ common) (NN stream) (CC or) (NN river) (NN system)))))))) (. .)))
A watershed is an area of land between mountain ridge lines in which all water drains into a common stream or river system.
(ROOT (S (NP (NP (DT All)) (PP (IN of) (NP (NP (DT the) (NN land)) (VP (VBN drained) (PP (IN by) (NP (DT a) (NN river) (NN system))))))) (VP (VBZ is) (VP (VBN called) (NP (NP (PRP$ its) (NN basin)) (, ,) (CC or) (NP (DT the) (`` ``) (JJ wet) ('' '') (NN term) (NN watershed)))))))