Problem: What are the most important words?
the rising sun on the opposite side of the sky gave the stunning pink colour tone to the rainbow
Answer: give, rise, sky, sun

Problem: What are the most important words?
A winter biathlon competitor crouching on a downhill to gain speed.
Answer: crouch, gain, speed

Problem: What are the most important words?
official poster of candidates of presidential election in front of a polling station
Answer:
candidate, election, poster