What are the keywords in the following sentence? A passenger train traveling through a tunnel covered with a forest.
forest, train, tunnel

What are the keywords in the following sentence? community members gathered on campus tuesday to protest the promenade .
gather, member, protest

What are the keywords in the following sentence? we wanted to discover more authentic foods and found this tour .
discover, food, tour

What are the keywords in the following sentence? a single shell encrusted rock on a sunny beach
beach, rock, shell