A long time ago，there was a craftsman．His name was Lu Ban. One day，he was at work on a mountain．A leaf cut his finger．He saw many sharp teeth on the leaf．"Could I make a____with teeth like these? I could cut things with it ____，"he said to____．Soon he made a saw. It was the first____in the world．People are____using this tool today．

孙中山领导的辛亥革命实现了20世纪中国第一次历史性巨变，因为这次革命(　　)。