4.(单选题,5.0分)-|||-对二元溶液,当恒温恒压条件下,下列各式中 Gibbs-Duhem 方程正确的形式是 ()()。-|||-A _(1)dln (y)_(1)+(x)_(2)dln (x)_(2)=0-|||-B _(1)dln (y)_(1)/d(x)_(1)+(x)_(2)dln (x)_(2)/d(x)_(2)=0-|||-() _(1)dln (y)_(1)/d(x)_(1)-(x)_(2)dln (y)_(2)/d(x)_(2)=0-|||-D _(1)dln (y)_(1)-(x)_(2)dln (y)_(2)=0