.1molbigcirc (1)(L)^-1 的下列二元酸中,用NaOH 标液滴定时,有两个滴定突跃的是-|||-()-|||-A _(2)S(O)_(4) (k)_(Q2)=(1.02)^circ (T)^-2-|||-B _(2)(C)_(2)(O)_(4) ka=5.6'(10)^-2 _(a2)=(1.5)^circ (10)^-4-|||-C 邻苯二甲酸 _(a1)=1.14'10-3 ._(a2)=3.70'10-|||-6-|||-D 铬酸 _(a1)=(1.8)^cdot (10)^-1 ,_(a2)=3.2'10'-7