21. The main idea of the passage is that:

Answer and Explanation

Your Answer is

Correct Answer is B

Explanation

Keynote

This article mainly introduces the great success of Waterfire and its huge impact on the city.

Item B: Waterfire brought Providence back to life.

Item A: The focus is not on Evans, but on Waterfire.

Item C: Public officals are not mentioned.

Item D: The symbolic meaning of waterfire is just a detail, not the main message.