根据短文内容，选择恰当的选项，使文章完整通顺。将序号填在横线上。

A. Then music was beautiful B. Susan was very proud. C. She was nervous. D. The children laughed.

    Susan played the piano in a concert last Sunday. She put the music book on the piano. Everyone listened. Then the seat broke and Susan fell. The teacher said, "Don't laugh!" The children clapped. .