精力充沛，乐观向上

An asian teacher in a checkered suit, a tie and a book in his hand, working with the class

An asian teacher in a checkered suit, a tie and a book in his hand, working with the class

Man in casual clothes standing

Man in casual clothes standing

Front view of a marching man

Front view of a marching man

Front view of an impressed man showing size of something

Front view of an impressed man showing size of something

Front view of a man in casual clothes covering ears with hands and looking at camera

Front view of a man in casual clothes covering ears with hands and looking at camera

Man standing in a room and shrugging his shoulders

Man standing in a room and shrugging his shoulders

Young asian man speaking into a microphone

Young asian man speaking into a microphone

Man in casual clothes standing

Man in casual clothes standing

Front view of a man with crossed fingers

Front view of a man with crossed fingers

Front view of a man in casual clothes covering eyes with hands

Front view of a man in casual clothes covering eyes with hands

Feeling myself just great

Feeling myself just great

Man in casual clothes standing

Man in casual clothes standing

Front view of a man with crossed fingers

Front view of a man with crossed fingers

Young asian man presenting a digital tablet

Young asian man presenting a digital tablet

Front view of a cheerful man in casual clothes showing thumbs up

Front view of a cheerful man in casual clothes showing thumbs up

Front view of a cheerful man in casual clothes showing thumbs up

Front view of a cheerful man in casual clothes showing thumbs up

Man in casual clothes walking

Man in casual clothes walking

Man in casual clothes explaining something

Man in casual clothes explaining something

Front view of a man with extended arm staring at someone

Front view of a man with extended arm staring at someone

Young asian man speaking into a microphone

Young asian man speaking into a microphone

Man in casual clothes standing

Man in casual clothes standing

Three-quarter view of a man in casual clothes listening attentively

Three-quarter view of a man in casual clothes listening attentively

Young asian man presenting a digital tablet

Young asian man presenting a digital tablet

Front view of a man in casual clothes holding fingers on lip and making faces

Front view of a man in casual clothes holding fingers on lip and making faces

Man in casual clothes standing still and lookin at something with interest

Man in casual clothes standing still and lookin at something with interest

Front view of a man with closed eyes standing with raised hands

Front view of a man with closed eyes standing with raised hands

Side view of a man in casual clothes marching

Side view of a man in casual clothes marching

Front view of a happy man waving

Front view of a happy man waving

Front view of a man in casual clothes looking through fingers

Front view of a man in casual clothes looking through fingers

Young man in orange sweatshirt standing

Young man in orange sweatshirt standing

Young asian man speaking into a microphone

Young asian man speaking into a microphone

Cheerful man shows thumb up

Cheerful man shows thumb up

Three-quarter view of a man in casual clothes covering eyes with hands

Three-quarter view of a man in casual clothes covering eyes with hands

An asian teacher in a checkered suit, a tie and a book in his hand, working with the class

An asian teacher in a checkered suit, a tie and a book in his hand, working with the class

Front view of a man in casual clothes listening attentively

Front view of a man in casual clothes listening attentively

Man in casual clothes posing

Man in casual clothes posing