What are the keywords in the following sentence? a helicopter flies over a village
fly, helicopter, village

What are the keywords in the following sentence? silhouette of loving couple inside the heart with butterflies .
couple, heart, silhouette

What are the keywords in the following sentence? an aircraft moves into position to receive fuel from cargo aircraft during a mission over country .
aircraft, country, mission, position, receive

What are the keywords in the following sentence? working tug boat guiding a large container ship through the narrow entrance of harbour
boat, entrance, guide, ship, work