What are the keywords in the following sentence? map showing the locations of stations for which data are analyzed
analyze, datum, location, map

What are the keywords in the following sentence? separate images taken by the spacecraft were combined to generate this view
combine, image, spacecraft, take

What are the keywords in the following sentence? illuminated palm trees in the street
illuminate, street, tree

What are the keywords in the following sentence? A herd of sheep grazing on top of a green field.
field, graze, herd, sheep, top