Can you help me with me speech?

I got an email message from Zhang Kai asking me to help him write a speech that is due next week.   He is very nervous about this even though he is an English major at Xian International University.  Zhang Kai was not my student but he is a person that everyone knows and I went to WuWei with him to speak at his Middle School.  He only has to speak for three minutes but from what I found out, Chinese students do not do public speaking like we do here.   I had asked my students to talk for 5 to 10 minutes and teach me new Chinese words.  That is when I found out they had never done anything like that before, not in English and not in Chinese.  I am trying to help Zhang Kai as much as I can.  He wrote me the topic, "a world that has changed the world."    First thing I asked was, "Is this the correct topic?"  I think it may be a word that changed the world, but in China you never know.  We will see how this goes.  I do keep in touch with my students and I enjoy finding things that I think could help them learn more about the English Language and the USA.  I was not Zhang Kai's teacher but he calls me Eric teacher.  Many of my students called me Eric Teacher.  I did like that.  Now all I need to do find out the topic and try my best to help my friend.  We will see how this goes.