1. (8 points) The calculation result of the expression $\frac{(1 \times 3 \times 5 \times 7 \times 9) \times(10 \times 12 \times 14 \times 16 \times 18)}{(5 \times 6 \times 7 \times 8 \times 9)^{2}}$ is
【Analysis】First, decompose the numerator part $10 \times 12 \times 14 \times 18$ into $2 \times 5 \times 2 \times 6 \times 2 \times 7 \times 2 \times 8 \times 2 \times 9$, then simplify through cancellation.
$$
\begin{array}{l}
\text { 【Solution】Solution: } \frac{(1 \times 3 \times 5 \times 7 \times 9) \times(10 \times 12 \times 14 \times 16 \times 18)}{(5 \times 6 \times 7 \times 8 \times 9)^{2}} \\
=\frac{1 \times 3 \times 5 \times 7 \times 9 \times 2 \times 5 \times 2 \times 6 \times 2 \times 7 \times 2 \times 8 \times 2 \times 1}{5 \times 6 \times 7 \times 8 \times 9 \times 5 \times 6 \times 7 \times 8 \times 9} \\
=2 ;
\end{array}
$$

The answer is: 2.