Problem: What are the most important words?
There is a zebra in his habitat at the zoo.
Answer: habitat, zebra, zoo

Problem: What are the most important words?
a bleeding protesters looks for paramedics after clashes between the riot police and protesters at a protest march
Answer: clash, look, police, protester

Problem: What are the most important words?
A brown bear in grass next to a fallen tree.
Answer:
bear, grass, tree