Supplement what you say with visual aids such as handouts, charts,

Supplement what you say with visual aids such as handouts, charts, transparencies, and slidestransparencies, and slides都是幻灯片，为何说二次

热心网友

transparencies是透明胶片, slides可以是储存在电脑中的powerpoint幻灯片

热心网友

transparencies是透明胶片(在展示台上用), slides可以是135正片(在幻灯机上用), 也可以是储存在电脑中的powerpoint幻灯片。