Traffic lights are very important for us. I think you know this. But do you know how they were born?
      Garrett A. Morgan was the father of traffic lights. He was an American. His family was very poor. He left school at the age of 14. He was clever. He always looked for better ways to do things. And he liked to make new things.
      At that time, every American wanted to have a car. The streets were full of cars. The traffic was really bad. “Why not put three lights at each corner ? They should be red_,green_,and yellow，” Morgan said , “ Let them tell cars to go or stop.” He made a timer (定时器)to change the lights.
     So we have traffic lights today .

①有丝分裂中期细胞        ②有丝分裂后期细胞         ③减数第一次分裂中期细胞

④减数第二次分裂中期细胞   ⑤减数第一次分裂后期细胞   ⑥减数第二次分裂后期细胞．

仿照下面的例句写一句话，使上下文自然顺畅。

  人生的价值不在于生命的长度，而在于生命的质量；人生的意义                   ，而在于                    。

右图是在戊戌变法中，中国近代由国家建立的第一所国家最高学府的招牌，它叫什么？在它也是今天一所著名大学的前身，这所著名大学的名称是什么？