Input: Identify the most salient words:

an ambulance being unloaded from yacht while it was serving as a ship

Output: serve
ship
yacht

Input: Identify the most salient words:

A train rounding a corner on the tracks.

Output: corner
round
track

Input: Identify the most salient words:

Two skiers racing each other down the slopes.

Output: race
skier
slope

Input: Identify the most salient words:

harbor in a small town in southern shooting boat in the port

Output:
boat
harbor
town