Problem: What are the most important words?
A piece of pizza in the box with cheese, mushrooms, and onions.
Answer: box, cheese, mushroom, onion, pizza

Problem: What are the most important words?
A baby is excitedly waving its arms and making noises.
Answer: arm, noise, wave

Problem: What are the most important words?
running trains in the city
Answer:
city, run, train