What are the keywords in the following sentence? girl is searching a book in the library
book, library, search

What are the keywords in the following sentence? a city looking towards region
city, look, region

What are the keywords in the following sentence? Herd of elephants traveling through the grass close to each other
elephant, grass, travel

What are the keywords in the following sentence? spacecraft manufacturer reveals image of cluster of newborn stars in the constellation
cluster, constellation, star