What are the keywords in the following sentence? firefighters are seen amongst the black smoke while battling the fire
fire, firefighter, smoke

What are the keywords in the following sentence? scrapped cars stacked on a scrap yard .
car, scrap, yard

What are the keywords in the following sentence? site listing category as seen
category, list, site

What are the keywords in the following sentence? A very tall brick clock tower surrounded by clocks on each of it's sides.
clock, surround, tower