Later, a friend of his had the idea that rubber might be made hard and strong if mixed with sulphur and put in the sun.

 
  • 后来,他的一个朋友发现在橡胶里掺入硫磺,经过日晒,可以使橡胶变得又硬又结实。
今日热词
目录 附录 查词历史