Problem: What are the most important words?
A train traveling down railroad tracks next to a grassy hillside
Answer: hillside, train, travel

Problem: What are the most important words?
He frantically sprints ahead, his eyes darting frantically to the other side.
Answer: dart, eye, side

Problem: What are the most important words?
view of the cruise ship passing under suspension bridge in the port
Answer:
bridge, pass, ship, view