Angola, one of Nigeria's trading partner countries, is trying to protect its domestic oil refineries from competition. To do so, it limits the amount of refined oil that can be imported from other countries. Which type of trade barrier is being described?

Americans often speak of their country as one of several large regions.  these regions are cultural units rather than governmental units --  formed by history and geography and shaped by the economics, literature and folkways that all the parts of a region share. what makes one region different from another? a region's multicultural heritage as well as distinct demographic characteristics like age and occupation make regions different and special. within several regions, language is used differently and there are strong dialects. there are also differences in outlook and attitude based on geography. 

Both types of rubrics