全部 » Lifestyle » Man » 分析黑板上写的方程式 Analyzing equations written on a blackboard

一个穿着西装的男人正在观察和分析写在他面前黑板上的方程式。老师在学校检查黑板。

Man dressed in a suit watching and analyzing equations written on a blackboard in front of him. Teacher checking the blackboard at school.