Input: Identify the most salient words:

water flows over a frozen waterfall

Output: flow
water
waterfall

Input: Identify the most salient words:

A woman jogs on a treadmill, and then walks on it for a few seconds.

Output: jog
treadmill
walk

Input: Identify the most salient words:

sign points the way up a city towards campus .

Output: city
point
sign
way

Input: Identify the most salient words:

firefighters responded to the emergency this morning

Output:
emergency
firefighter
respond