Input: Identify the most salient words:

Smoke billows from the train travelling down the track.

Output: billow
track
train

Input: Identify the most salient words:

plastic bag floating over reef in the ocean

Output: bag
float
ocean
reef

Input: Identify the most salient words:

This is an image of a bench overlooking a beach.

Output: beach
bench
overlook

Input: Identify the most salient words:

The roar of his engine and clank of his chains recede as the biker gradually dissolves into thin air.

Output:
air
clank
dissolve
engine
recede