4.下列结论正确的是 ()-|||-(A) (int )_(-infty )^+infty dfrac (x)(1+{x)^2}dx=0 (B) (int )_(-infty )^edfrac (1)(x)dx=0-|||-(C) (int )_(-dfrac {pi )(2)}^dfrac (pi {2)}((e)^x-(e)^-x)sin xdx=0 (D) (int )_(-1)^1sqrt [3](x(x+1)(x-1))dx=0