Final answer:
Prince Edward Island is connected to mainland Canada by the Confederation Bridge, one of the longest continuous multispan bridges in the world, connecting the island with New Brunswick.
Step-by-step explanation:
The province that is connected to mainland Canada by one of the longest continuous multispan bridges in the world is Prince Edward Island. This bridge is known as the Confederation Bridge, and it spans the Abegweit Passage of Northumberland Strait, connecting Prince Edward Island with New Brunswick. Completed in 1997, the Confederation Bridge measures 12.9 kilometers (8 miles) in length and is a significant engineering achievement that facilitates transportation and commerce between the island and the mainland.