( ( Rotary style ) ( ( may ( be ( ( ( driven ( by ( direct current ) ) ) or ) ( alternating ( current ( electricity source ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Rotary) (NN style)) (VP (MD may) (VP (VB be) (VP (VP (VBN driven) (PP (IN by) (NP (JJ direct) (NN current)))) (CC or) (VP (VBG alternating) (NP (JJ current) (NN electricity) (NN source)))))) (. .)))
Rotary style may be driven by direct current or alternating current electricity source.
(ROOT (S (NP (VBG Alternating) (NN current)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (JJ electric) (NN current))) (SBAR (WHNP (WDT that)) (S (VP (VBZ keeps) (S (VP (VBG reversing) (NP (NN direction))))))))) (. .)))