문제가
a week ago, i was at home with my brother.
i ( ) a book when i heard a strange sound out of the window.
에서 ()에 답이 was reading라고 합니다.
제 생각엔 read의 과거형 read라고 생각해요.
was reading인 이유와 왜 read가 안되는지 이야기해주세요