Sinkholes are formed by precipitation.
Sinkholes are common in the southwestern portion of the subsection.
Precipitation is common in the southwestern portion of the subsection.
What is common in the southwestern portion of the subsection?
a) permineralization
b) deuterostomes
c) barrel-shaped
d) cactuses
e) swamp vegetation
f) peachleaf willow
g) precipitation
h) gene flow