What are the keywords in the following sentence? passengers on board a flight
board, flight, passenger

What are the keywords in the following sentence? A zebra grazes short grass growing between trees.
grass, graze, tree, zebra

What are the keywords in the following sentence? towering cloud above the sea and volcanic rocks
cloud, sea, tower

What are the keywords in the following sentence? i just thought this piece looked really cool .
look, piece, think