西元前
BC adv : before the Christian era; used following dates before the supposed year Christ was born; "in 200 BC" [syn: {B.C.}, {before Christ}]
BC An {arbitrary precision} numeric processing language with {C}-like {syntax}. Traditionally implemented as a front-end to {DC}. There is a {GNU} version called {GNU BC}. {Unix manual page}: bc(1).