mothball
n
1 small ball made of a strong-smelling substance, used for keeping moths away from stored clothes 衛生球; 樟腦丸.
2 (idm 習語) in `mothballs stored and not used for a long time 封存不用
old aircraft kept in mothballs 封存的舊飛機.
??? 情景例句
During your computer classes, did they teach you how to fix a cooling fan?