曲线的参数方程是 $\left\{\begin{array}{l}x=1-\frac{1}{t} \\ y=1-t^2\end{array}\right.$ ( $t$ 是参数, $\left.t \neq 0\right)$, 它的普通方程是
$\text{A.}$ $(x-1)^2(y-1)=1$
$\text{B.}$ $y=\frac{x(x-2)}{(1-x)^2}$
$\text{C.}$ $y=\frac{1}{(1-x)^2}-1$
$\text{D.}$ $y=\frac{x}{1-x^2}+1$