WHEN WHILE
1. The students were doing an exercise
2. I saw an accident.
3.
4. He fell down
5.
6. We found some old photographs
7.
8. I had a bad dream
9.
10. She started to cry
the bell rang.
I was waiting at the bus stop.
she was writing an email, her computer turned off.
he was climbing a tree.
my mom came home, my sister was sleeping.
we were tidying our room.
you called me last night, I was studying for the test.
I was sleeping on the sofa.
the fire alarm went off, we were listening to music.
she was watching a movie.
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