What are the keywords in the following sentence? players and soccer player enter the stadium prior to a friendly match between country
country, enter, stadium

What are the keywords in the following sentence? biological species walking on the ground
ground, specie, walk

What are the keywords in the following sentence? Hikers are crossing a stream.
cross, hiker, stream

What are the keywords in the following sentence? moving shot from the ground through forest and leaves in autumn
autumn, leave, shot