Input: Identify the most salient words:

nurse putting oxygen mask on a female patient in hospital corridor

Output: mask
nurse
patient
put

Input: Identify the most salient words:

the centre of the city with the town hall

Output: centre
city
hall

Input: Identify the most salient words:

gate to restrict entrance to the construction site

Output: entrance
gate
site

Input: Identify the most salient words:

a cross in heaven surrounded by rays of light .

Output:
light
ray
surround