Answer:
medium of exchange
Explanation:
Because it just makes sense
-South Africa richest country in minerals
-Oil: Nigeria, Angola, Equatorial Guinea, Gabon
-Diamonds: Botswana, DR of Congo, Republic of South Africa, Namibia
-Uranium: Namibia, Niger, Malawi, Republic of South Africa
-Strategic minerals: Republic of South Africa, DR of Congo, Rwanda
-Copper: Zambia, DR of Congo, Republic of South Africa
The correct answer is: A. Lunar phase.
Sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by groundwater circulating through them. As the rock dissolves, spaces and caverns develop underground.
Sinkholes are formed when the land surface above collapses or sinks into the cavities or when surface material is carried downward into the voids. Drought, along with resulting high groundwater withdrawals, can make conditions favorable for sinkholes to form.
