Multiple choice

Directions: Fill in the blank.

They had scarcely heard the siren ________ they ran for their life.

  1. when

  2. than

  3. hardly

  4. then

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sentence is implying a sense of time in regards to the missing word. With this in mind, 'when' is the only option that fits.