Adapted practice prompt

图书馆排班冲突

You are a university student. a mandatory academic event conflicts with your scheduled library shift. Write an email to Library Supervisor to apologize, explain the conflict, and propose a shift exchange.

In your email, do the following:

1. 1Apologize directly for the change or inconvenience.
2. 2Explain the reason briefly without making excuses.
3. 3Propose a fair alternative or next step.

根据主题改编，非 ETS 官方原题。