Enseignant ou élève barbu porte des lunettes, s'assoit à table avec des livres, déconcentré. Homme sur le visage excité entre des piles de livres à la bibliothèque, étagères sur fond. Concept de découverte scientifique . - Photo & image de stock

Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific research concept. Man on thoughtful face between piles of books in library, bookshelves on background.

Man on happy face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific research concept.

Time flow concept. Teacher or student with beard studying in library. Man on serious face watching time is going over, bookshelves on background. Man, scientist in glasses looks at hourglass.

Time flow concept. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass. Man on surprised face holds hourglass while studying, bookshelves on background.

Man, nerd on surprised face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Nerd concept.

Time flow concept. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass. Man on serious face watching time is going over, bookshelves on background.

Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Man on thoughtful face between piles of books in library, bookshelves on background. Scientific research concept.

Man on shocked face between piles of books, while studying in library, bookshelves on background. Deadline concept. Teacher or student with beard sits at table with glasses, defocused.

Man, scientist peeking out of piles of books with alarm clock. Teacher or student with beard studying in library. Time flow concept. Man on happy face looking at clock, bookshelves on background.

Man on busy face reading book, bookshelves on background. Education and science concept. Scientist sits at table with eyeglasses and hourglass. Teacher or student with beard studying in library.

Man, scientist peeking out of books. Teacher or student with beard studying in library. Man on serious and strict face watching time is going over, bookshelves on background. Time flow concept.

Man on thoughtful face holds hourglass while studying, bookshelves on background. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass. Time flow concept.

Man on thoughtful face holds hourglass while studying, bookshelves on background. Teacher or student with beard studying in library. Time flow concept. Man, scientist in glasses looks at hourglass.

Time flow concept. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass. Man on serious face watching time is going over, bookshelves on background.

Man on thoughtful face holds hourglass while studying, bookshelves on background. Man, scientist in glasses looks at hourglass. Time flow concept. Teacher or student with beard studying in library.

Man on strict face sit between piles of books, while studying in library, bookshelves on background. Teacher or student with beard sit at table with glasses, defocused. Bookworm concept.

Man on thoughtful face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific research concept.

Bearded man with lots of books preparing for exams

Scientific discovery concept. Man on shocked face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused.

Man on nervous face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific discovery concept.

Man on surprised face holds hourglass while studying, bookshelves on background. Time flow concept. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass.