choose the correct words.
1. While I walked / was walking home from school, I saw an accident.
2. When I saw / was seeing the accident, I called the police.
The police arrived / was arriving very quickly.
4. While they talked / were talking to the driver, an ambulance arrived.
5 While my sister tidied / was tidying her room, she found her homework, o.She was very hapoy when she found was finding her homework.