( ( Review ( ( the types ) ( of ( simple machines ) ) ) ) . )
(ROOT (NP (NP (NNP Review)) (NP (NP (DT the) (NNS types)) (PP (IN of) (NP (JJ simple) (NNS machines)))) (. .)))
Review the types of simple machines.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD six) (NNS types) (NNS types)) (PP (IN of) (NP (JJ simple) (NNS machines))))) (. .)))