What are the keywords in the following sentence? an image of a train going in a railroad
image, railroad, train

What are the keywords in the following sentence? Someone pulls the pin from his grenade.
grenade, pin, pull

What are the keywords in the following sentence? olympic athlete saves a penalty during the match on day .
match, penalty, save

What are the keywords in the following sentence? gardens like this one devoted to research and breeding trials cover several acres of the property .
acre, garden, property