用化学用语填空：

（1）磷的元素符号为____ ；（2）两个锌离子　____ ；

（3）二氧化硫中硫元素显+4价　____ 　；（4）13号元素原子的结构示意图为____ ；

（5）空气中含量最多的气体是____ ；（6）人体胃酸的主要成分是　____ ．

已知椭圆 $E：\frac{x^2}{a^2}+\frac{y^2}{b^2}=1\left(a>b>0\right)$ 的离心率为 $e=\frac{1}{2}$ ，左右焦点分别为F₁，F₂，以椭圆短轴为直径的圆与直线 $x-y+\sqrt{6}=0$ 相切．

（Ⅰ）求椭圆E的方程；

（Ⅱ）过点F₁、斜率为k₁的直线l₁与椭圆E交于A，B两点，过点F₂、斜率为k₂的直线l₂与椭圆E交于C，D两点，且直线l₁，l₂相交于点P，若直线OA，OB，OC，OD的斜率k_OA，k_OB，k_OC，k_OD满足k_OA+k_OB=k_OC+k_OD，求证：动点P在定椭圆上，并求出此椭圆方程．

如图，矩形OABC的边OA长为2 ，边AB长为1，OA在数轴上，以原点O为圆心，对角线OB的长为半径画弧，交正半轴于一点，则这个点表示的实数是

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    There are few families in the United States that do not have either a radio or television set. Both of them have become a necessary part of our daily life, keeping us filled with the news of the day, teaching us in many fields of interest, and making us happy with singing, dancing and acting.
    Marconl, the Italian inventor, who gave us the radio, probably didn't know how much his great invention would have done for the world in the years to come. Radio had, perhaps done as much as any other communication tool. Things of the world can be reported to people everywhere a few seconds after they happen. Travelers in or out of–the–way places, ships at sea even astronauts round the earth are able to keep in touch with each other by radio.
    Television is another important invention. It lets us see as well as hear the actor. Since its appearance, TV has done a great deal in the daily life of people everywhere. Many programs are now televised in color.
    Perhaps the most modern invention is “Telstar”, a “star” moving round the earth. It makes it possible for the people all over the world to be closer than ever before. Now a family in Chicago can watch on TV a motor–car race in Italy, a table tennis competition in Beijing or a volleyball match in Japan as these events are actually happening!