What are the keywords in the following sentence? butterfly rests on a leaf
butterfly, leaf, rest

What are the keywords in the following sentence? A red traffic light in front of a blue sky.
front, light, sky

What are the keywords in the following sentence? religious leader meets with politician on the occasion of their private audience
audience, leader, meet, politician

What are the keywords in the following sentence? australian suburb of the most livable cities in the world
city, suburb, world