1 2 Y~-|||-0 1 7-|||-设X~ 1/3 2/3 J 1/2 1/2 X+Y=2 =1/6, 则-|||-(A) P(X=Y )=1/3 (B) X=Y =1/6-|||-(C) X=1+Y =2/3 (D) X=Y+1 =5/6-|||-A. (C)-|||-B. (B)-|||-C.(D)-|||-D.(A)