( Clouds ( ( form ( as ( ( ( a result ) ( of condensation ) ) ( driven ( by ( adiabatic cooling ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Clouds)) (VP (VBP form) (SBAR (IN as) (S (NP (NP (DT a) (NN result)) (PP (IN of) (NP (NN condensation)))) (VP (VBN driven) (PP (IN by) (NP (JJ adiabatic) (NN cooling))))))) (. .)))
Clouds form as a result of condensation driven by adiabatic cooling.
(ROOT (S (NP (NNP Condensation)) (VP (MD must) (VP (VB occur) (PP (IN for) (NP (NNS clouds))) (S (VP (TO to) (VP (VB form)))))) (. .)))