What are the keywords in the following sentence? time lapse of moving cloud on a blue sky
cloud, lapse, sky

What are the keywords in the following sentence? serious students listening a lecturer in an amphitheater
lecturer, listen, student

What are the keywords in the following sentence? An man is riding an elephant on the walkway.
elephant, ride, walkway

What are the keywords in the following sentence? a woman laying flowers in place alongside others following the siege
flower, follow, lay