Past Simple vs Past Continuous

While I watched / was watching TV, my sister was doing her homework

My friends often phoned / were often phoning me when my parents were out.

While (tidy) my room, (find) some old photographs

While I was talking to my friend, I realised / was realising that something was wrong.

As we (leave) the cinema, (realise) that I'd left my phone behind.

The power went out WHILE / WHEN I was having breakfast.

It was a lovely day. The sun shone / was shining and the birds sang / were singing.

My computer (crash) while I (update) my web page

While Simon (watch) television, his brother (cook) dinner.

When we (hear) the fire alarm, we all (stop) what we (do) and (walk) out of the building.

Lionel Messi won / was winning a gold medal for Argentina in the Beijing Olympics.

They arrived AS / WHEN we were leaving.

I was walking home WHILE / WHEN it started to rain.