学校的选修课或选修科目的英文

optional course or subject studied at school or college

• 学校:    school; educationa ...
• 的:    4次方是 The fourth po ...
• 选修课:    elective course; s ...
• 或:    nǎi-.
• 选修:    take as an electiv ...
• 科目:    subject; course