( ( Because ( air ( has mass ) ) ) ( , ( ( ( Earth 's ) gravity ) ( ( ( ( attracts it ) and ) ( ( gives it ) weight ) ) . ) ) ) )
(ROOT (S (SBAR (IN Because) (S (NP (NN air)) (VP (VBZ has) (NP (NN mass))))) (, ,) (NP (NP (NNP Earth) (POS 's)) (NN gravity)) (VP (VP (VBZ attracts) (NP (PRP it))) (CC and) (VP (VBZ gives) (NP (PRP it)) (NP (NN weight)))) (. .)))
Because air has mass, Earth's gravity attracts it and gives it weight.
(ROOT (S (NP (NNP Gravity)) (VP (VBZ attracts) (NP (DT the) (NN earth)) (PP (TO to) (NP (DT the) (NN sun)))) (. .)))