Input: Identify the most salient words:

a bolt of cloud to cloud lightning flashes as a summer storm moves into the city

Output: city
cloud
move
storm

Input: Identify the most salient words:

smoke billows from a building on a farm

Output: billow
building
smoke

Input: Identify the most salient words:

The sound of the car radio can be heard coming from inside.

Output: hear
radio
sound

Input: Identify the most salient words:

beach scattered with shells in the early autumn morning

Output:
beach
morning
shell