Input: Identify the most salient words:

fans add to the colour on show at their clash .

Output: add
colour
fan

Input: Identify the most salient words:

aircraft on landing approach at the airport

Output: aircraft
airport
approach

Input: Identify the most salient words:

protest to soccer official after he awarded a penalty

Output: award
official
penalty

Input: Identify the most salient words:

white swans and ducks float on water in a lake .

Output:
duck
float
lake
swan
water