Jawaban:

1. The teacher was teaching the students when I was paying.

2. Mr Wahyu was explaining the lesson while Budi was talking.

3. Susi was listening to music when I called her.

4. My mother was cooking while I cleaned the house.

5. Razid was studying English when Susi wrote a letter.

6. The doctor was checking the patients while the nurse prepared the medicine.

7. The boys were playing football when the girls were dancing.

8. I was reading a novel when the girls were singing.

9. Alice was painting a flower when the boys were drawing.

10. Ded was washing the car when I got home.