Problem: What are the most important words?
a boat with tourists passes a herd of biological species
Answer: boat, pass, tourist

Problem: What are the most important words?
A kitchen area with a microwave, a refrigerator, a sink and a tile floor.
Answer: area, floor, microwave, refrigerator

Problem: What are the most important words?
Two zebra's standing next to one another eating grass.
Answer:
eat, grass, standing