Question

select the appositive or appositive phrase. george perkins marsh, one of the first environmentalists in the united states, condemned the detrimental effects of the industrial revolution on the american landscape.

Explanation:

The appositive phrase here is "one of the first environmentalists in the United States" as it renames or provides additional information about the noun "George Perkins Marsh".

Answer:

one of the first environmentalists in the United States