What are the keywords in the following sentence? map of the region indicating many of the locations referred to in text
indicate, map, region

What are the keywords in the following sentence? the average number of thunderstorm days per year .
day, number, year

What are the keywords in the following sentence? A train is in the distance traveling down the tracks.
distance, track, travel

What are the keywords in the following sentence? a black crow perched on a tree
crow, perch, tree