What are the keywords in the following sentence? an inshore fishing boat returning up a city to the harbour
boat, city, harbour

What are the keywords in the following sentence? athlete walks off the pitch after being sent off by athlete during the match .
athlete, pitch, walk

What are the keywords in the following sentence? an airplane stands on the tarmac in the airport .
airplane, airport, stand, tarmac

What are the keywords in the following sentence? A group of planes near control tower in an airport.
airport, plane, tower