( ( The ( class U ) ) ( ( was ( ( a ( 4-6-0 ( four-cylinder ( compound locomotive ) ) ) ) ( which ( used ( ( de Glehn ) ( compound system ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN class) (NNP U)) (VP (VBD was) (NP (NP (DT a) (JJ 4-6-0) (JJ four-cylinder) (NN compound) (NN locomotive)) (SBAR (WHNP (WDT which)) (S (VP (VBD used) (S (NP (NNP de) (NNP Glehn)) (VP (VB compound) (NP (NN system))))))))) (. .)))
The class U was a 4-6-0 four-cylinder compound locomotive which used de Glehn compound system.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD four) (NNS classes)) (PP (IN of) (NP (JJ biochemical) (NNS compounds))))) (. .)))