What are the keywords in the following sentence? image of military helicopter is hovering in the blue sky while doing patrols
helicopter, hover, sky

What are the keywords in the following sentence? tractor ploughing a field followed by seagulls
field, follow, plough, seagull

What are the keywords in the following sentence? day out at a petting farm and a feast of food in poster
day, farm, pet

What are the keywords in the following sentence? A small heard of giraffes are walking through the terrain.
giraffes, terrain, walk