Final answer:
The Great Lakes St. Lawrence Lowlands are situated in both Southern Ontario and Southern Quebec, areas with fertile farmland and historic significance from early French colonization.
Step-by-step explanation:
The Great Lakes St. Lawrence Lowlands are located in both Southern Ontario and Southern Quebec. This region is known for its fertile farmland and is bordered by the Appalachian Mountains to the south and the Canadian Shield to the north. Notably, this region, especially the area surrounding the St. Lawrence River, was an important part of early French colonization in Canada.