Answer:
As he headed to Room 10 at the end of the corridor after getting off the bus at the music school, Jerry mentally studied the correct trombone slide positions. He sat down in front of the music stand, eagerly smiling at his teacher, Nadine, who gave him an odd look.
She inquired, "Where's your trombone?"
“Oh no!” exclaims the speaker. He'd forgotten about it on the bus! After explaining the issue to Nadine, he said, "What will I do?"
"You have to return it, otherwise your parents will lose $900."
"Oh no," says the speaker. In despair, he clapped his hands to his face.
She didn't give him a lesson and sent him home. The bus ride back was excruciatingly painful. It reminded him of the last bus, which had been the scene of the disaster.