Problem: What are the most important words?
black sheep and white sheep graze a lush green pasture in front of a beautiful red barn .
Answer: front, graze, sheep

Problem: What are the most important words?
texture of moss and lichen growing on the bark of a tree
Answer: bark, grow, texture, tree

Problem: What are the most important words?
footballer smiles during a training session .
Answer:
footballer, session, smile