La Guerra Fría comenzó porque Europa perdió poder al final de la Segunda Guerra Mundial. Esto dejó a la Unión Soviética y a los Estados Unidos compitiendo por el gobierno económico y militar. Ambos países creían que sus políticas eran las mejores y, en última instancia, querían que todos los demás siguieran. (The Cold War started because Europe lost power at the end of World War II. This left the Soviet Union and the United States competing for economic and military rule. Both countries believed their policies were the best and ultimately wanted all others to follow.)
If I understand your meaning your saying what to expect in the future. I think we will have a better understanding of more and more creatures in the ocean
A. Spanish conquistadors bring their horses with them across the Atlantic. Some horses escape or swim to shore after a ship sinks. The Plains Indians become expert horsemen and buffalo hunters.
This was certainly not intentional since hardly the conquistadors would want their enemies to be stronger.
B. B. Rats are aboard European ships coming to the Americas. The rats spread disease and hunt unknown numbers of smaller animals to extinction.
This is hardly intentional. Rats were almost unavoidable back then and the Europeans just did not care much about them. They weren't thinking about how the rats would cause trouble in the Americas. They were "just rats".
So the only intentional one is:
C. Columbus brought pigs to the Americas on his second voyage. The pigs provided a valuable source of food for a growing population.
Columbus brought pigs for them to serve as food eventually and so they did.
In the early 19th century the owners of sugar plantations faced a huge problem. This was witnessed by water shortage as well as lack of labor.
