Final answer:
The mouths of the four major rivers in the Middle Atlantic States are Delaware Bay, Chesapeake Bay, New York Harbor, and the Chesapeake Bay.
Step-by-step explanation:
The mouth is the point where a river meets a lake or ocean. In the Middle Atlantic States, there are four major rivers: the Delaware River, the Susquehanna River, the Hudson River, and the Potomac River. These rivers have different mouths, with the Delaware River flowing into Delaware Bay, the Susquehanna River flowing into Chesapeake Bay, the Hudson River flowing into New York Harbor, and the Potomac River flowing into the Chesapeake Bay.