Final answer:
The two major landforms of the Saint Lawrence Lowlands are the St. Lawrence River Valley and the Appalachian Mountains. The St. Lawrence River Valley is a lowland region, while the Appalachian Mountains are a mountain range.
Step-by-step explanation:
The two major landforms of the Saint Lawrence Lowlands are the St. Lawrence River Valley and the Appalachian Mountains.
The St. Lawrence River Valley is a lowland region that stretches along the St. Lawrence River. It is a flat and fertile area with important agricultural activities, such as dairy farming and agriculture.
The Appalachian Mountains, on the other hand, are a mountain range located to the south of the St. Lawrence River Valley. They form a natural barrier between the lowlands and the Canadian Shield.