What are the keywords in the following sentence? A pizza with ham and vegetables on a serving tray
pizza, tray, vegetable

What are the keywords in the following sentence? add a felt to the middle of the chains
add, chain, middle

What are the keywords in the following sentence? celebrity leaves airport after charming the crowds on sunday morning .
airport, celebrity, leave

What are the keywords in the following sentence? a map tracing the journeys made by explorer
explorer, journey, map