Problem: What are the most important words?
An airplane parked on top of an airport tarmac.
Answer: airplane, park, tarmac

Problem: What are the most important words?
city was barely visible on monday morning with a fog covering the skyscrapers and parts of the river
Answer: city, cover, fog, morning

Problem: What are the most important words?
young colt staying close to mother grazing fresh grass in a paddock
Answer:
grass, graze, mother, paddock, stay