You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
--------
Question: Category: INVENTORS & INVENTIONS 
Clue: Invented by Philip Drinker in the 1920s, this closed respirator is used by patients who can't breathe on their own

Answer: an iron lung


Question: Category: ORGANIZATIONS 
Clue: This service "Club" has a 4-way test of things they think, say & do, including "Will it be beneficial to all concerned?"

Answer: the rotary club


Question: Category: CINCO DE MAYO 
Clue: Tchaikovsky conducted this New York City landmark's opening concert May 5, 1891

Answer:
carnegie hall