Povijest - 2009./10. ljeto - 31.

A. kamen $\to \backslash rightarrow$ željezo $\to \backslash rightarrow$ bakar $\to \backslash rightarrow$ bronca

B. kamen $\to \backslash rightarrow$ bronca $\to \backslash rightarrow$ željezo $\to \backslash rightarrow$ bakar

C. kamen $\to \backslash rightarrow$ željezo $\to \backslash rightarrow$ bronca $\to \backslash rightarrow$ bakar

D. kamen $\to \backslash rightarrow$ bakar $\to \backslash rightarrow$ bronca $\to \backslash rightarrow$ željezo