下列结论正确的是-|||-(A)(int )_(-infty )^+infty dfrac (x)(1+{x)^2}dx=0. (B)| (x/(1+2)^2 (1+x^2)^2 dx=0.-|||-(C) (int )_(-1)^1dfrac (1)(sin x)dx=0. (D) (int )_(-infty )^+infty (e)^-|x|dx=1.