Why do studies conducted in theory-testing mode de-emphasize ecological validity?

In the modern world, many countries with kings or queens have evolved into constitutional democracies. in these countries, monarchs are mostly

Why did jefferson oppose the assumption of the debt

Which statement below best explains the main goal of manifest destiny during the 1800's? a to create an alliance between the united state and the mexican empire b to expand america's borders across the entire north american continent c to remove native americans from the united states' territory completely d to move settlers north of the great lakes to claim land from great britain