a prize certificate / a certificate of completion or diploma

(architecture) paper sliding doors

detailed explanation

explain in detail

vanishing, disappearance, removal, erasure

(intransitive) to vanish, to disappear / (transitive) to make something vanish or disappear, to remove, to erase

promotion to a higher grade or rank

be promoted, advance

sight (device used in aiming a firearm)

fruit fly (Drosophilidae)