( ( Make ( an ( effort ( to ( learn ( ( ( the location ) ( of ( air masses ) ) ) ( that ( affect ( ( the weather ) ( of ( the ( United States ) ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (VP (VB Make) (NP (DT an) (NN effort) (S (VP (TO to) (VP (VB learn) (NP (NP (DT the) (NN location)) (PP (IN of) (NP (NN air) (NNS masses))) (SBAR (WHNP (WDT that)) (S (VP (VBP affect) (NP (NP (DT the) (NN weather)) (PP (IN of) (NP (DT the) (NNP United) (NNPS States))))))))))))) (. .)))
Make an effort to learn the location of air masses that affect the weather of the United States.
(ROOT (S (NP (NP (DT The) (JJS best) (NN explanation)) (PP (IN for) (SBAR (WHADVP (WRB how)) (S (NP (NN air) (NNS masses)) (VP (VBP move) (PP (IN across) (NP (DT the) (VBN united) (NNS states)))))))) (VP (VBZ is) (SBAR (IN that) (S (NP (DT the) (VBG prevailing) (NNS westerlies)) (VP (VP (VBP move) (NP (NN air) (NNS masses)) (PP (IN from) (NP (NN west))) (PP (TO to) (ADJP (JJ east))) (PP (IN across) (NP (DT the) (VBN united) (NNS states)))) (CC but) (VP (MD may) (VP (VB be) (VP (VBN deflected) (PP (IN by) (NP (DT the) (NN jet) (NN stream)))))))))) (. .)))