-2-引 9-22( k+ 2k-1 k三0 三房(g-空ws 33 1 ( ) 2 0 0 1 1 ( ) ! 2 ! 2 x k l z z k l k l x x e z z k l 1 2 0 0 ( 1) ! ! 2 x k l l z z k l k l x e z k l 2 0 ( 1) ( ) ( )! ! 2 l l n n n n n l n x z J x z n l l