A perforated state is a state that .
is completely surrounded by another state
serves as a buffer between two much larger states
completely surrounds another state
stretches a long way in one direction, but a comparably short way in the other direction
is small and highly centralized
If the political barrier between two states is the 50th parallel on the lines of latitude, then the boundary between those two states is known as a(n) .
arithmetic frontier
physical boundary
geometric boundary
intermediate boundary
buffer state