These are trade alliances. When companies between these countries trade they have to worry less about customs and importing and things like that and crossing the border is much easier because the goal is to boost the economy of all signatory parties.<span />
Because it is more accurate, faster, and cheaper than useing lead weights on a line.
The answer is D,<span>One culture adopts features from a nearby culture for its own benefit...</span>
Shanties are not the average place to stay , and are often depicted as areas of despair. However, there is increased recognition that the slums are indeed source of home for several rural impoverished people who can not manage to migrate to the affluent urban areas forthright. It is a starting point after all. Better half a pie than lack of it altogether.