记$$f\left( t \right)={{\left( {{\log }_{2}}3 \right)}^{t}}-{{\left( {{\log }_{5}}3 \right)}^{t}}$$，  则$$f\left( t \right)$$在$$\mathbf{R}$$上是严格增函数．  原不等式即$$f\left( x \right)\geqslant f\left( -y \right)$$．  故$$x\geqslant -y$$，  即$$x+y\geqslant 0$$． 
若$${{\left( {{\log }_{2}}3 \right)}^{x}}-{{\left( {{\log }_{5}}3 \right)}^{x}}\geqslant {{\left( {{\log }_{2}}3 \right)}^{-y}}-{{\left( {{\log }_{5}}3 \right)}^{-y}}$$，则（  ）．
* $$x-y\geqslant 0$$ 
* $$x+y\geqslant 0$$ 
* $$x-y\leqslant 0$$ 
* $$x+y\leqslant 0$$ 