What are the keywords in the following sentence? stack of books scattered on the floor in the library
book, floor, stack

What are the keywords in the following sentence? A guy is opening his robe and putting a clamp on his nipple.
clamp, nipple, put

What are the keywords in the following sentence? is in action during her first round match at the tennis
action, match, tennis

What are the keywords in the following sentence? american football player in action with football player during their match at football ground
action, ground, match, player