Problem: What are the most important words?
cats need to be examined by a veterinarian if they stop eating .
Answer: cat, examine, veterinarian

Problem: What are the most important words?
living sea shells in the sea
Answer: live, sea, shell

Problem: What are the most important words?
concrete gravity dams are constructed such that their own weight resist the forces exerted upon it
Answer:
construct, dam, exert, force, weight