What are the keywords in the following sentence? shallow reef extending to the horizon off the coast
coast, horizon, reef

What are the keywords in the following sentence? 2 nurses showing the proper way to bandage someon'es head.
bandage, head, nurse

What are the keywords in the following sentence? young couple relaxing on board of the yacht
board, couple, yacht

What are the keywords in the following sentence? low flight over the wheat field in sunny day
day, field, flight