先化简 $\left(\frac{x}{x-5}-\frac{x}{5-x}\right)÷\frac{2x}{x^2-25}$ ，然后从不等组 $\{\begin{array}{c}-x-2\le 3\\ 2x<12\end{array}$ 的解集中，选取一个你认为符合题意的x的值代入求值．

B、C 和 D 项中选出最佳选项。

    Canton Tower is the highest tower in China.1 you stand on top of the tower, you can get a bird's-eye view of the Pearl River. At weekends, people in Guangzhou often visit the tower with 2families. Visitors are 3in taking photos of the city at the tower.

    In 2005, workers 4 to build this tower. In 2010, the colorful lights of the tower lighted up the sky for the first time. People spend over four years 5 it.

    Canton Tower is in the center of our city. It is  6to get there by bus or by underground. We can also find 7useful information of the tower on the Internet. For example, there 8 a 4D cinema in it. The tower is open 9 9 a.m. to 11 p.m.

    For people of Guangzhou, Canton Tower is 10work of art and a new symbol of our city.