What are the keywords in the following sentence? soldiers stand alongside their armored vehicles
soldier, stand, vehicle

What are the keywords in the following sentence? food bought from a supermarket
buy, food, supermarket

What are the keywords in the following sentence? commuters waiting for the metro at the metro station
metro, station, wait

What are the keywords in the following sentence? stranded tourists waiting outside airport during a curfew on monday .
airport, monday, wait