( ( ( A hailstone ) ( that ( is ( ( the size ) ( of ( a golfball ) ) ) ) ) ) ( ( needs ( ( ( an updraft ) ( of ( nearly 60 ) ) ) ( mph ( to ( stay aloft ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN hailstone)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (NP (NP (DT the) (NN size)) (PP (IN of) (NP (DT a) (NN golfball)))))))) (VP (VBZ needs) (S (NP (NP (DT an) (NN updraft)) (PP (IN of) (NP (QP (RB nearly) (CD 60))))) (ADJP (NN mph) (S (VP (TO to) (VP (VB stay) (ADVP (RB aloft)))))))) (. .)))
A hailstone that is the size of a golfball needs an updraft of nearly 60 mph to stay aloft.
(ROOT (S (NP (NNP Birds)) (VP (VBP need) (NP (DT a) (JJ light-weight) (NN body)) (PP (IN for)) (S (VP (TO to) (VP (VB stay) (ADVP (RB aloft)))))) (. .)))