题目

On Sunday，April 22，people all over the world take times out to appreciate（珍惜）file earth that we all share．It's Earth Day，a special day to learn about our planet（星球）and how to take care of it． On Earth Day，some people listen to speeches about the environment（环境）．Others help clean up their offices or save water anti electricity at home．Your parents may even decide to take a day off from driving their car． The idea for Earth Day came from a U．S．Senator（参议员），who was worried about pollution and the health of plants and animals．And the idea8．椭圆$\frac{x^2}{13}+\frac{y^2}{4}=1$的焦点为F1，F2，点P是椭圆上的动点，当∠F1PF2为钝角时，点P的横坐标的取值范围是$（-\frac{{\sqrt{65}}}{3}，\frac{{\sqrt{65}}}{3}）$．