①一定存在某个位置E，两天经过此地的时刻相同

②一定存在某个时刻，两天中在此刻的速度相同

③一定存在某一段路程EF（不含A、B），两天在此段内的平均速度相同．（以上速度不考虑方向）

正确说法的序号是____．

阅读下文，回答相关问题。

                                                                               荷包蛋
      一天早晨，父亲做了两碗荷包蛋面条。一碗蛋卧上边，一碗上边无蛋。端上来，父亲问儿子，“吃哪一碗？”
     “有蛋的那碗！”儿子指着卧蛋的那碗。“让爸吃那碗有蛋的吧！”父亲说：“孔融7岁能让梨，你10岁啦，该让蛋吧！”
     “孔融是孔融，我是我——不让！”儿子态度坚决。
     “真不让？”“真不让！”儿子一口就把蛋给咬了一半。
     “别后悔？”“不后悔！”儿子又一口，把蛋吞了下去。待儿子吃完，父亲开始吃。当然父亲碗里藏了两个荷包蛋，儿子看得分明。
     “记住：想占便宜的人，往往占不到便宜！”父亲指着碗里的荷包蛋告诫儿子。
      儿子显出一脸的无辜。
      第二次，那是个星期天的上午，父亲又做了两碗荷包蛋面条。一碗蛋卧上边，一碗上边无蛋。端上桌，问儿子：“吃哪碗？”
    “孔融让梨，我让蛋！”儿子笑着端起了无蛋的那碗。
    “不后悔？”“不后悔！”儿子说得坚决。
      儿子吃到底，也不见一个蛋。父亲的碗里，上卧一个，下藏一个，儿子看得分明。
     “记住，想占便宜的人，可能要吃亏！”父亲指着蛋教训儿子说。
      第三次，父亲又做了两碗荷包蛋面条，还是一碗卧上边，一碗上边无蛋。
      父亲问儿子：“吃哪碗？”
     “孔融让梨，儿子让面——爸爸您是大人，您先吃！”儿子手一挥做“绅士”状。
     “那就不客气啦！”父亲端过上边卧蛋的那碗，儿子发现了自己碗里藏卧着的荷包蛋。
     “不想占便宜的人，生活也不会让他吃亏！”父亲意味深长的对儿子说。

    I have a friend named Monty Roberts who owns a horse ranch(牧马场). The last time I was there he told me his story. When he was young, his family was too poor to have a house to live in.As a result , when he was in high school, all the students were asked to write a paper about what they wanted to be and do when they grew up. That night he wrote a seven-page paper describing his goal of owning a horse ranch. He also drew a picture to show a 4,000-square-foot house that would sit on a beautiful farm. The next day he handed it in to his teacher. Two days later he received his paper back. On the front page was a large red F. Roberts asked, “Why did I receive an F?” He teacher said, “This is an unrealistic dream for a young boy like you. Owning a horse ranch requires a lot of money.” Then the teacher added, “If you will rewrite this paper with a more realistic goal, I will reconsider your grade.”

    The boy went home and thought about it for a long and hard time. He asked his father what he should do. His father said, “ Look, son, you have to make up your own mind on this. However, I think it is a very important decision for you.”Finally, after sitting with it for a week, the boy turned in the same paper, making no changes at all. He told his teacher “you could keep the F and I still keep my dream”.

    He tells me this story because I am sitting in his 4,000-square-foot house in the middle of the 200-acre horse ranch. “I still have that school paper now.” He added, “The best part of the story is that two years ago that  teacher brought 30 kids to camp out on my ranch for a week.” When the teacher was leaving, he said, Look, Monty, I can tell you this now. When I was your teacher, I was something of a dream stealer.During those years I stole a lot of kids' dreams. Luckily, you had enough gumption not to give up on yours. .”