<span>The exposed portion of the continental
crust underlying North America refers to Canadian Shield. The continental crust
is known as the North American Craton which consists of rocks from the Archean
dn Proterozoic eons and extends from Mexico to Greenland. Canadian Shield also
produces great resources that helped most humans for their economic
development. Because of the resources present in the Shield, it has a great
disadvantage to settlers. The primary obstacle to population growth in the area
is the presence of the bare rock, thin soils, muskeg and insects. So the answer is letter A.</span>
Answer:
The jet stream shifts north and south seasonally; because there is less cold air, it retreats northward into Canada during the northern hemisphere's summer
Explanation:
the answeris fjdklsfjdslfj A sorry
