Question 4: I was doing my homework _______________the light went out.
The past continuous indicates an action in progress when another action interrupted. + The action in progress is divided into the past continuous form: was/were + V-ing.
+ Interjection action in the simple past: Vpast.
Eg: How to use when and while.
– I was doing my homework when the light went out. (When the lights go out, I’m doing my homework)
– While I was doing my homework, the light went out.(The light went out while I was doing my homework)
=> EASY answer
===============