What are the keywords in the following sentence? a temple built into a mountain
build, mountain, temple

What are the keywords in the following sentence? student receiving an exam from the teacher at classroom
classroom, receive, student

What are the keywords in the following sentence? olive trees grow on a farm in the region .
farm, region, tree

What are the keywords in the following sentence? many clues about the origin may be gained by studying the moon .
clue, moon, origin