What are the keywords in the following sentence? Smoke billows from a locomotive going down the tracks.
billow, locomotive, track

What are the keywords in the following sentence? stuffed mushrooms make a great appetizer or even main dish .
dish, mushroom, stuff

What are the keywords in the following sentence? traffic is building approaching bridge
approach, bridge, traffic

What are the keywords in the following sentence? empty wooden pier with dark stormy clouds over sea and yellow fishing boat in the distance
cloud, distance, sea