Problem: What are the most important words?
a herd of elephants with wet skins leaving from the waterhole at which they have been drinking
Answer: drink, herd, waterhole

Problem: What are the most important words?
automobile model is based on platform .
Answer: base, model, platform

Problem: What are the most important words?
A class room with numerous laptops at desks with chairs.
Answer:
chair, desk, laptop, room