Problem: What are the most important words?
Two moped enthusiasts are having a conversation.
Answer: conversation, enthusiast, mope

Problem: What are the most important words?
small orange mushrooms grow on a log in a damp forest
Answer: forest, grow, log, mushroom

Problem: What are the most important words?
ecology the study of how organisms interact with their environment
Answer:
ecology, environment, interact, organism, study