What are the keywords in the following sentence? image of books on a shelf
book, image, shelf

What are the keywords in the following sentence? following the ridge on the eastern trail
follow, ridge, trail

What are the keywords in the following sentence? A football player with a football is being pursued by another player.
football, player, pursue

What are the keywords in the following sentence? a woman supporting country stands next to demonstrators rallying in support .
demonstrator, rally, support