题目

We’ve all had cases where we’ve waited just a bit too long to pay an electric bill or speeding ticket. But one man, from California by reasonable assumption，who goes by “Dave”，recently took procrastination (拖延) one step further, by paying a parking ticket almost a half-century after it was given.In December 2018, the Minersville Police Department in Pennsylvania received a letter in the mail. Whoever wrote the letter decided it was best to keep his name somewhat unknown，so he put the return address as “Wayward Road，Anytown California” under the name “Feeling guilty”10．如图所示，直线AB，CD相交于点O，OE平分∠AOC，OF平分∠BOD，请求出∠EOF的度数．有什么发现？能用一句简洁的语句描述你的发现吗？