Problem: What are the most important words?
rugby player sports his bruises during a recovery session in a swimming pool .
Answer: player, session, sport

Problem: What are the most important words?
biological kingdom growing at the base of an old tree
Answer: grow, kingdom, tree

Problem: What are the most important words?
Two giraffes nuzzle each other in a zoo as the others search the ground.
Answer:
giraffes, nuzzle, zoo