( ( Name ( ( the ( two types ) ) ( of ( wave speed ) ) ) ) . )
(ROOT (S (VP (VB Name) (NP (NP (DT the) (CD two) (NNS types)) (PP (IN of) (NP (NN wave) (NN speed))))) (. .)))
Name the two types of wave speed.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD two) (NNS types)) (PP (IN of) (NP (NN surface) (NNS waves))))) (. .)))