Problem: What are the most important words?
Sheepherders move their sheep across a highway as vehicular traffic passes between their flock.
Answer: flock, highway, sheep

Problem: What are the most important words?
A woman talks about beads and the colors of them, they look like small marbles.
Answer: color, marble, talk

Problem: What are the most important words?
a tree survives and thrives after half of it is split away by lightning
Answer:
half, split, tree