Если верить проверенным источникам
то это или мини мелодия (типо ренгтона) ну или просто короткая музыка
1 Is it an orange? общий
2 What is it?
1. I was reading a book when my mother came in.
2. He was taking a shower when the lights went off.
3. The rain started to fall while we were walking in the park.
4. We were eating our dinner when someone knocked on the door.
5. They were walking to school when suddenly they saw an unusual light.
1 true
2 true
3 false
4false
5 false
6 false
7 true
8 true