Problem: What are the most important words?
a car for sale at a dealership in a city
Answer: car, city, sale

Problem: What are the most important words?
the umbrella is not optimally placed to protect the occupants of the chairs
Answer: chair, occupant, protect, umbrella

Problem: What are the most important words?
an airplane is being loaded with cargo in preparation for departure
Answer:
airplane, departure, preparation