Problem: What are the most important words?
and it is possible to rent a boat and go around the lake .
Answer: boat, lake, rent

Problem: What are the most important words?
machinery working on the construction of new road in summer day
Answer: construction, road, work

Problem: What are the most important words?
A beach covered in lots of lawn chairs and umbrellas.
Answer:
beach, chair, cover, lot, umbrella