侯德榜发明的制碱工艺被化工界命名为“____ ”。

一个男子把X染色体上的某一突变基因传给儿子的概率是（ ）

一定条件下的密闭容器中：4NH₃（g）＋5O₂（g）4NO（g）＋6H₂O（g）+3623KJ；下列叙述正确的是（      ）

      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 .