What are the keywords in the following sentence? a duke crew member waits to be hoisted up by helicopter during a training session .
helicopter, member, session

What are the keywords in the following sentence? face of innocence ... some smiles are straight from the heart .
face, heart, smile

What are the keywords in the following sentence? a studio portrait of a family comprising mother and father with their children one holding a doll
family, mother, portrait

What are the keywords in the following sentence? the apartment is recently renovated by industry for sale .
apartment, industry, sale