Answer:
Defletion hollows: Defletion hollows are ever wind has removed sand down to a level where a layer of particles is too heavy for the wind to move stabilises the sand and prevent the surface being lowered further. It's also known as blow out dune.
Explanation:
Sorry ,I only know about this so i can't tell u of others
The rate of natural increase refers to the difference between the number of live births and the number of deaths occurring in a year, divided by the mid-year population of that year, multiplied by a factor (usually 1,000). It is equal to the difference between the crude birth rate and the crude death rate.
