Answer: World War I Begins
On July 28, Austria-Hungary declared war on Serbia, and the tenuous peace between Europe's great powers quickly collapsed.
Explanation:
There were of course other factors. While early humans did hunt them a lot due to the profits which they received from it (A lot of food, bones they could use for homes, fur they could use for clothing, etc.), there were also other factors such as less food for them which made them less mobile through different geographical regions, etc. (and therefore more susceptible to being hunted) that had played a part in their extinction.
1. La calzada romana
uso:destacaban la movilización de grandes ejércitos con una rapidez nunca vista
Hormigón
uso:permitió que los edificios construidos no estuvieran solamente hechos de piedras apiladas y mortero.