下列反常积分收敛的是
$\text{A.}$ $\int _{0}^{1} \dfrac {dx}{ \sqrt {x}(x-1)} $
$\text{B.}$ $\int _{0}^{+ \infty } \dfrac { \sqrt {x}}{1+x \sqrt {x}}dx$
$\text{C.}$ $\int _{1}^{+ \infty } \dfrac {dx}{ \sqrt {x^{2}-x}} $
$\text{D.}$ $\int _{0}^{1} \dfrac {dx}{ \sqrt {x-x^{2}}}$