1. $\frac{11!-10!}{9!}=(\quad)$.
(A) 99
(B) 100
(C) 110
(D) 121
(E) 132
1. B.
$$
\begin{array}{l}
\frac{11!-10!}{9!}=\frac{11 \times 10 \times 9!-10 \times 9!}{9!} \\
=11 \times 10-10=100 .
\end{array}
$$