Make the students do not understand the lesson. There are no Etiquette: teachers. Do not understand the lesson content. Dear friend, not as a burden on other people's work, others have to wait.
The students do not understand the lessons Uncultured teachers No understanding of the course content Dear friends behind A burden to others Make others wait
Make the students understand the lesson. No manners on teachers understand the course content, learning without friends, burden of others. Make others waiting.