Question

fill preposition they stopped working ----- sunset​

Answer 1

they stopped working at sunset

Answer 2

Answer:

The correct statement will be -

They stopped working at sunset.

Explanation:

Here a particular time or period of the day has been mentioned,i.e. sunset and hence 'at' is the most appropriate preposition to be used here.

For a specific time or place that has been mentioned, 'at' should be used. It denotes specificity.