( ( Simple Machines ) ( ( ( Grades ( 3-4 Looks ) ) ( at ( ( all types ) ( of ( simple machines ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Simple) (NNPS Machines)) (VP (VBZ Grades) (NP (CD 3-4) (NNS Looks)) (PP (IN at) (NP (NP (DT all) (NNS types)) (PP (IN of) (NP (JJ simple) (NNS machines)))))) (. .)))
Simple Machines Grades 3-4 Looks at all 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))))) (. .)))