解析:圆D:(x-√3)^2+(y-1)^2=3D(√庆缓扮3,1)设AD倾角为α,BD倾角为β,AB倾角为π/6AB与AD夹角为∠1=α-π/6AB与BD夹角为誉灶∠2=π/6+π-β由圆的性质可哪首知∠1=∠2∴α-π/6=π/6+π-β==>α+β=4π/3选择C