1 17. (B ) 1 ( ) ) ) l ng( ) ) A ( ) B ( ) (1) chu n( ) ) l ng( ) ) (2) 2 ( ) (1) zh (2) (3) 3 ) (x ) ) ) (ju ) 4 ) 2016 11 16 (li n) (p n) ) ) 5 y ny n(1) y n(4) 6 2 7 sh chu ng 8 ( ) 180 A(A. B ) _B(A. B ) (1) (xi ng) (ch ) (2) 9 ( ) (1) (2) p ng (3) 10 pi o zhu n ku i 11 hu b n 12 3 (1) ( ) (A.x B (B) B (A) (2) ) ) 13 14 15 16 17 zh n 18 19 z o 20 xu n 21
