( ( Describe ( how ( ( simple machines ) operates ) ) ) . )
(ROOT (S (VP (VB Describe) (SBAR (WHADVP (WRB how)) (S (NP (JJ simple) (NNS machines)) (VP (VBZ operates))))) (. .)))
Describe how simple machines operates.
(ROOT (S (S (NP (DT A) (JJ complex) (NN machine)) (VP (VBZ is) (VP (VBN described) (PP (IN by))))) (: :) (S (NP (PRP it)) (VP (VBZ is) (VP (VBN made) (PP (IN of) (NP (QP (JJR more) (IN than) (CD one)) (JJ simple) (NN machine)))))) (. .)))
A complex machine is described by: it is made of more than one simple machine.