χ[img=~/QImg/2013-10-14-11-12-39/image001.jpg]界值表的取值范围

A、-∞<χ[img=~/QImg/2013-10-14-11-12-39/image001.jpg]<∞
B、-∞<χ[img=~/QImg/2013-10-14-11-12-39/image001.jpg]<0
C、O<χ[img=~/QImg/2013-10-14-11-12-39/image001.jpg]<∞
D、-1<χ[img=~/QImg/2013-10-14-11-12-39/image001.jpg]<1
E、χ[img=~/QImg/2013-10-14-11-12-39/image001.jpg]≤1