Input: Identify the most salient words:

surgeons operating on a patient in the medical block

Output: operate
patient
surgeon

Input: Identify the most salient words:

killer whales spotted tuesday afternoon on a whale watching vessel off a city .

Output: city
spot
whale

Input: Identify the most salient words:

floating autumn leaf on the water surface of pond

Output: float
leaf
pond

Input: Identify the most salient words:

trunk and bark of a fir tree in woodland

Output:
bark
tree
woodland