What are the keywords in the following sentence? building is in the heart of the city
building, city, heart

What are the keywords in the following sentence? looking over a city from the hill behind the visitor centre
centre, hill, look

What are the keywords in the following sentence? a girl living in a remote place travels kilometres for drinking water
live, place, travel

What are the keywords in the following sentence? heavy smoke was still coming from the home about a hour after the fire started .
come, fire, home, smoke