Problem: What are the most important words?
a tug arrives at the stern of a container ship ready to assist the ship depart from port
Answer: assist, port, ship, tug

Problem: What are the most important words?
statue of liberty at island .
Answer: island, liberty, statue

Problem: What are the most important words?
row of shops with their goods for sale on the pavement outside
Answer:
good, pavement, shop