Problem: What are the most important words?
Several zebras eat grass in a zoo habitat.
Answer: eat, grass, habitat, zebra

Problem: What are the most important words?
politician and his wife share a meal
Answer: politician, share, wife

Problem: What are the most important words?
fireworks explode over greek revival structure after a public concert and appearance by politician
Answer:
concert, explode, firework, politician, structure