Answer:
Wikipedia defines formal sector as activities which are taxed and monitored by the government and the activities involved are included in the Gross Domestic Product(GDP).
Explanation:
In contrast to formal economy is the informal sector which is neither taxed nor included in the GDP and Gross national product (GNP) of a country.
Answer:
Afghanistan's mountains have kept the country from ever being invaded.
Explanation:
Afghanistan is a country in terrible conditions, and this is not the case just nowadays but it has been like that for a very long time. Despite all of the internal troubles of the country and it seems to be very weak in pretty much every sector, it has never been invaded in the past few centuries, and very rarely in the more distant history and always it has been short-lasting.
The main reason for this has been the mountains and the general geography of the country. Very high and rugged mountains are separating the country from potential invaders. Even if an invading force manages to go through the mountains, it will suffer great losses just by doing so, and what comes next is desert and more rugged terrain, which will further damage them, so by the time they engage in battle, they will be too weak to conquer Afghanistan.
Urban areas are characterized by high population density when compared to other areas
Areas that are located on the outskirts of cities or large urban areas but retain rural characteristics such as agricultural productions are generally considered as peri urban areas
The arafura sea lies between australia and melanesia