Final answer:
The Great Lakes are connected to the Atlantic Ocean by the St. Lawrence Seaway, which provides a trade route for ships.
Step-by-step explanation:
The Great Lakes are connected to the Atlantic Ocean by the St. Lawrence Seaway. This seaway provides a deepwater ship route, connecting the Great Lakes to the Atlantic Ocean through the St. Lawrence River. It allows ships to travel from the lakes to the ocean, facilitating trade and navigation.