Problem: What are the most important words?
A train travels a distance on top of train tracks
Answer: distance, track, travel

Problem: What are the most important words?
the sun rises over sea as a ship passes on the horizon .
Answer: horizon, pass, sea, ship

Problem: What are the most important words?
country told to brace for a winter with lots of snow
Answer:
brace, country, lot, snow, tell