What are the keywords in the following sentence? canopy of tall gum trees contrasted against an aurora like evening sky .
contrast, sky, tree

What are the keywords in the following sentence? forest the vines have damaged this small tree and many around it
forest, tree, vine

What are the keywords in the following sentence? the boy is undergoing treatment in the hospital
hospital, treatment, undergo

What are the keywords in the following sentence? Three pairs of rusty scissors hanging from nails.
hang, nail, pair, scissor