Input: Identify the most salient words:

Subway train station with a stopped train on only one side.

Output: stop
subway
train

Input: Identify the most salient words:

two males are on some grass playing frisbee

Output: frisbee
grass
male

Input: Identify the most salient words:

a heron is perched on its nest at the top of a tree

Output: heron
perch
tree

Input: Identify the most salient words:

cats in a flowering meadow

Output:
cat
flower
meadow