( ( ( -LRB- ( ( 3 pts ) -RRB- ) ) ( ( air ( gasoline aluminum-magnesium ) ) ( alloy ( ( ( ( ( N 2 ) ( -LRB- ( g -RRB- ) ) ) and ) ( Ar ( -LRB- ( g -RRB- ) ) ) ) ( ( mixture none ) ( of ( ( the ( above Which ) ) ( of ( the following ) ) ) ) ) ) ) ) ) ( ( is ( a ( pure ( elemental substance ) ) ) ) ? ) )
(ROOT (S (SBAR (PRN (-LRB- -LRB-) (ADJP (QP (CD 3) (CD pts))) (-RRB- -RRB-)) (S (NP (NN air) (NN gasoline) (NN aluminum-magnesium)) (VP (VBZ alloy) (NP (NP (NP (NNP N) (CD 2)) (PRN (-LRB- -LRB-) (NP (NN g)) (-RRB- -RRB-))) (CC and) (NP (NP (NNP Ar)) (PRN (-LRB- -LRB-) (NP (NN g)) (-RRB- -RRB-))) (NP (NP (NN mixture) (NN none)) (PP (IN of) (NP (NP (DT the) (JJ above) (NN Which)) (PP (IN of) (NP (DT the) (NN following)))))))))) (VP (VBZ is) (NP (DT a) (JJ pure) (JJ elemental) (NN substance))) (. ?)))
(3 pts) air gasoline aluminum-magnesium alloy N 2 (g) and Ar(g) mixture none of the above Which of the following is a pure elemental substance?
(ROOT (S (NP (NNP Air)) (VP (MD can) (VP (VB be) (VP (VBN separated) (PP (IN into) (NP (JJ several) (NNS elements)))))) (. .)))