( ( ( C or ) cooled ) ( ( ( using ( liquid nitrogen ) ) ( to ( ( -73 & ) degree ) ) ) ; ) )
(ROOT (S (NP (NNP C) (CC or) (NNP cooled)) (VP (VBG using) (NP (JJ liquid) (NN nitrogen)) (PP (TO to) (NP (NP (CD -73)) (CC &) (NP (NN degree))))) (: ;)))
C or cooled using liquid nitrogen to -73&degree;
(ROOT (S (NP (NN Liquid) (NN nitrogen)) (VP (VBZ is) (VP (VBN used) (PP (IN for) (NP (NP (VBG cooling) (NNS detectors)) (PP (IN of) (NP (JJ infrared) (NNS telescopes))))))) (. .)))