gěi lǎoshī fā yóujiàn shí, biāotí xiě qīngchu kèchéng, xìngmíng hé wèntí, bǐrú zhōngwén èrbān ānnà zuòyè tíjiāo wèntí

给老师发邮件时，标题写清楚课程、姓名和问题，比如“中文二班-安娜-作业提交问题”。

When emailing a teacher, write the course, name, and issue clearly in the subject line, such as 'Chinese Class Two - Anna - Homework Submission'.