What are the keywords in the following sentence? real estate agent aiding a young couple who is putting up their home for sale
agent, couple, home

What are the keywords in the following sentence? bridge and tower in a sunny day
bridge, day, tower

What are the keywords in the following sentence? smiling lecturer helping his student in the library at the university
help, lecturer, library, smile, student

What are the keywords in the following sentence? A train lets off some exhaust as it exits the station
let, station, train