(QT (DQL ``) (QTC (S (S (BASENP (PRP It)) (VP (VP (VBZ is) (ADVP (RB virtually))) (ADJP (JJ impossible) (PP (IN for) (S (BASENP (NN water)) (VP (PRN (COMMA ,) (PP (IN in) (NP (BASENP (DT the) (NN form)) (PP (IN of) (BASENP (NN vapor))))) (COMMA ,)) (VP (TO to) (VP (VB be) (ADJP (JJ absent) (PP (IN from) (BASENP (DT the) (NN planet)))))))))))) (COMMA ,) (S (ADVP (RB so)) (S (BASENP (PRP it)) (VP (MD must) (VP (VB be) (VP (VBN hidden) (COMMA ,) (PP (ADVP (RB probably)) (PP (IN by) (NP (BASENP (DT the) (JJ dusty) (NN cloud) (NN layer)) (SBAR (S (BASENP (PRP we)) (VP (VBD detected) (PP (IN in) (BASENP (PRPD our) (NN spectrum))))))))))))))) (PERIOD .)) (DQR ''))