Unequal heating of earth 's surface by the sun causes global wind patterns.
Another major type of wind is called a polar easterly.
Unequal heating of earth 's surface by the sun causes polar easterlies.
Unequal heating of Earth 's surface by what causes polar easterlies?

a) sun
b) UV
c) drag
d) wind
e) loch
f) ovens
g) lightbulbs
h) blankets