Input: Identify the most salient words:

passengers watching mass transportation system pulling in

Output: passenger
pull
watch

Input: Identify the most salient words:

columns leading into a cloister at one of many churches in old town

Output: church
cloister
lead

Input: Identify the most salient words:

ideas for giving cash as a gift

Output: gift
give
idea

Input: Identify the most salient words:

A train moves through the city on its tracks.

Output:
city
move
track