Answer:
Not only did Bolivar face the full strength of Spanish forces; he also had to contend with the difficult, mountainous terrain of South America. He turned this challenge, however, into an advantage, when he surprised Spanish forces by crossing the Andes and capturing Bogota.
Nationalism can unify a country by having a sense of superiority over other countries.
Answer:
For the Aztecs, the enviroment was more benevolent. The aztecs inhabited Central Mexico which is a highland area where temperatures are mild. Soils are also very fertile because they are volcanic. The biggest challenge they had to face was precisely the active volcanoes that sorround the Central Valley of Mexico.
For the Mayans, the enviroment was more unforgiving. They inhabited a lowland tropical jungle with high humidity and temperatures all-year round. The soils were not very fertile either.
It has been theorized that the Mayan civilization disappeared because of deforestation, which led to a rise of temperatures and a general worsening of enviromental conditions.