Problem: What are the most important words?
A pizza is topped with ham, pineapple, mushrooms, and extra cheese.
Answer: cheese, ham, pineapple, pizza, top

Problem: What are the most important words?
roast beef, carrots and onions on a plate with water
Answer: beef, carrot, plate

Problem: What are the most important words?
A train traveling down train tracks next to a guard rail.
Answer:
rail, track, train