1. She was eating/ate an apple when she found a worm in it.
2. They couldn’t get into the cinema while the film was showing/showed.
3. What were you doing/did you do at the time when the police caught you?
4. When Stephen was arriving home/arrived home, I was eating dinner.
5. The student don’t listen/wasn’t listening when the teacher gave the instruction.
1.ate
showing
3.did
4.arrived
5.wasn't