What are the keywords in the following sentence? close up of a tiny green and yellow spider in its web
close, spider, web

What are the keywords in the following sentence? a tour boat departs the pier for tourist attraction
boat, depart, pier

What are the keywords in the following sentence? a fire engine responds to a call during a blizzard
call, engine, respond

What are the keywords in the following sentence? crowds of tourists push forward on a rainy day
crowd, day, push