What are the keywords in the following sentence? students doing homework on a laptop
homework, laptop, student

What are the keywords in the following sentence? a train speeding down a track in the city
speed, track, train

What are the keywords in the following sentence? port with a cruise ship in front
front, port, ship

What are the keywords in the following sentence? A worker climbs up scaffolding for his last shift of the day
climb, scaffold, worker