19 ч 30 мин, 29 май 1957 г. - The Federal Aid to Education program stimulates sales of overhead projectors
Описание:
The invent of overhead projectors was a cost effective measure for instructional technology in that it gave a means to present a single document or visual to large numbers without printing multiples.Добавлено на ленту времени:
Дата:
19 ч 30 мин, 29 май 1957 г.
Сейчас
~ 67 г назад
