Why have locks been created between the Great Lakes and the St. Lawrence River? A.
elevation between the areas is different

B.
to slow the shipping that goes through them

C.
to produce hydroelectricity

D.
to prevent flooding

A. elevation between the areas is different

Explanation:

-The locks have been created between the Great Lakes and the St. Lawrence River because of the elevation between the areas is different. The Great Lakes and the St Lawrence River with the Atlantic Ocean are linked by St Lawrence Seaway which is a system of locks, canals and channels. The seaway provides passage for oceangoing vessels into central North America.

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