What are the keywords in the following sentence? an ancient stone monument next to grass and blue skies
grass, monument, sky

What are the keywords in the following sentence? mushrooms growing on a side of a tree
grow, mushroom, side

What are the keywords in the following sentence? Several people walk up a slope as others are coming down at an intersect.
come, slope, walk

What are the keywords in the following sentence? shoppers walk past the entrance
entrance, shopper, walk