( Crow ( sometimes ( ( repaired ( ( refrigeration equipment ) ( that ( contained ( ozone-depleting compounds ) ) ) ) ) . ) ) )
(ROOT (S (NP (NNP Crow)) (ADVP (RB sometimes)) (VP (VBD repaired) (NP (NP (NN refrigeration) (NN equipment)) (SBAR (WHNP (WDT that)) (S (VP (VBD contained) (NP (JJ ozone-depleting) (NNS compounds))))))) (. .)))
Crow sometimes repaired refrigeration equipment that contained ozone-depleting compounds.
(ROOT (S (NP (NN Ozone)) (VP (VBZ is) (NP (NP (DT a) (NN compound)) (VP (VBN formed) (SBAR (WHADVP (WRB when)) (S (NP (EX there)) (VP (VBZ is) (VP (VBG sparking) (NP (JJ electrical) (NN equipment))))))))) (. .)))