Input: Identify the most salient words:

large block retaining walls on each side of the driveway .

Output: driveway
retain
side
wall

Input: Identify the most salient words:

white rowing boat full of flowers on an island in a pond

Output: flower
island
pond

Input: Identify the most salient words:

Five sheep in their enclosure, one of them has their head through the rails.

Output: enclosure
head
rail

Input: Identify the most salient words:

tourists on the bow of a ship being pulled by tug

Output:
bow
pull
ship
tourist
tug