Federal law doesnt mandate it
Answer:
I believe it's a unnatural vs natural
Explanation:
A human border is aline that separates 2 political/geographical areas.
like Iraq's border with turkey
and..
a physical boundary is a naturally occurring barrier between 2 or more areas. including oceans , cliffs.
Human activities contribute change- by change in the earths surface
Speed of response is not correlated with iq scores
