Answer:
The reason for this is because the Monte Alban pyramid complex was completely abandoned by the year 1000 AD due to socio-economic problems. In fact, wealth disparity and the over exploitation of natural resources were the two primary causes of the decline of all of the ancient civilization.
I believe it was the use of poisonous gasses, which they not only used on the Jews but in war too......., or The newly created Machine gun<span />
