The geologic record indicates that a dessert expands and contracts in response to altering dry and wet climatic periods, whether there is any human intervention.
a)
b) with or without human intervention.
c) when there is human intervention and when there is none.
d) human intervention or not.
e) no matter whether humans intervene.
a)
b) with or without human intervention.
c) when there is human intervention and when there is none.
d) human intervention or not.
e) no matter whether humans intervene.
