Restrictive vs. Non-restrictive Elements Answer
2
The American students knew by heart the exploits of Davy Crockett, a legendary
American war hero, but they knew nothing about Wovoka or Meister Eckhart or any
spiritual leader but their own.
Answer: Correct!
Commentary:
Here "a legendary war hero" refers back to Davy
Crockett. However, there is only one Davy Crockett. Therefore, this is already
well-specified, and it should be set off with commas.