Input: Identify the most salient words:

cells are the basic structural units of living organisms .

Output: cell
live
organism

Input: Identify the most salient words:

the plane flies between layers of clouds

Output: cloud
fly
layer

Input: Identify the most salient words:

polar bears biting and wrestling behind the willows and snow

Output: bear
bite
snow
willow
wrestle

Input: Identify the most salient words:

crowds celebrate as the results of the vote are announced

Output:
announce
celebrate
result