What are the keywords in the following sentence? A tray of food with broccoli, tomatoes and pasta salad in it.
broccoli, food, tray

What are the keywords in the following sentence? Subway train station with a stopped train on only one side.
side, stop, train

What are the keywords in the following sentence? a city a fortress built at the end of eleventh century by adherents
build, century, city

What are the keywords in the following sentence? has the world always looked as it does today what was a city
city, look, world