folder

n cover for holding loose papers, etc, made of stiff material, esp cardboard, folded together 文件夹; 纸夹.

focsle, focus, focus on, focus...on, fodder, foe, foetal (US fetal), foetus (US fetus), fog, fog-bank, fog-bound, fog-horn, fog-lamp, foggy, fogy (also fogey), foible, foil, foist, fold, foldaway, folding, foliage, folio, folk, folk-dance, folk-music (also folk), folk-song, folk-tale, folklore, folklorist, folks, folksy, foll, follow, follow (in) sb's footsteps, follow out, follow through, follow up, follow-on, follow-through, follow-up,