为什么knowledge is treasure treasure是不可数的

treasure: [ 'tre? ]n. 宝物,财富v. 珍爱,重视,储藏例句与用法:1. this museum has many art treasures.这家博物馆收藏了许多艺术珍品.2. such a lesson should be treasured in our memories.这样的宝贵教训应...