a или an: cep, plasticine, paintbrush, chalk, crayon, ink, feltpen, marker, compasses (в мн. ч), alidad, puncher, pencil pot, glue, gluestick, sticker, scotch tape, scissors, stapler, staple remover, correction fluid, correction tape, paper clips, drawing pin, magnet, calculator, desk organizer, map, globe, atlas, encyclopedia, spike, record book, colouring book, folder, whiteboard. Пожалуйста умоляю!! Помогите очень нужно срочно!