Which of the following sentences correctly uses an adjective in the superlative degree?

Which adverb is correctly formed from the adjective "quick"?

Complete the sentence with the correct forms of the adjectives:

"Niagara Falls is one of the _______ waterfalls in North America, renowned for its stunning beauty. However, Angel Falls in Venezuela is the _______ waterfall in the world, with a drop of 3,212 feet."