A major obstacle to creating policies that address the issue of global warming is the conflict between
А
economic development and environmental protection,
B
migrant workers and the native labor force.
socialist governments and democratic governments.
D
nations that produce oil and nations that don't

A

Explanation:

Regulations often come at the price of economic developement

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.