5. In what regions have volcanoes in the United States have been
concentrated?

Pacific West Region

Explanation:

Most of these volcanoes are found in the Aleutian Islands, the Alaska Peninsula, the Hawaiian Islands, and the Cascade Range of the Pacific Northwest; the remainder are widely distributed in the western part of the Nation.

9) a & b

10) true.

11) false.

12) false.

13) true.

14) false.

15) true.

16) true.

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