Correct the sentences according to the text.
1. The centre of Nahanni National Park is the Mackenzie Mountains,
2. The name Nahanni means "the land of the Naha people
3. The South Nahanni River runs into Niagara Falls.
4. The Second Canyon has the highest walls.
5. Niagara Falls are higher than Virginia Falls.
6. Nahanni National Park has four climatic zones.
7. Alexander Mackenzie came to Naha to find gold.