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.
'Climatic variations' and 'Human activities' can be regarded as the two main causes of desertification. removal of the natural vegetation cover（by taking too much fuel wood）, agricultural activities in the vulnerable ecosystems of arid and semi-arid areas, which are thus strained beyond their capacity.
I believe the answer is A, but Im not 100% I hope this helps!
Answer:
Plate Tetonics
Explanation:
Plate interactions, as a result of plate tectonics, ultimately generate the various geologic settings where Earth materials can melt, metamorphose, and/or weather to become sediments.
