Re-order paragraphs

c) Sometime about a million and a half years ago, some forgotten genius of the hominid world did an unexpected thing. He (or very possibly she) took one stone and carefully used it to shape another.

a) The result was a simple teardrop-shaped hand-axe, but it was the world’s first piece of advanced technology.

d) It was so superior to existing tools that soon others were following the inventor’s lead and making hand-axes of their own.

b) Eventually whole societies existed that seemed to do little else.