A man in a striped polo shirt stands on stage in front of a chalkboard while holding a microphone .
A teacher is teaching his students .
A man in a striped polo shirt stands on stage in front of a chalkboard while holding a microphone.
A teacher is teaching his students.
There's a guy talking, but you do not know if he's a teacher, and he does not show students.
There 's a guy talking , but you do not know if he 's a teacher , and he does not show students .