bed·rock /-ˈrɑk, ˌrɑk/
岩床,根底,基礎
bedrock
n 1: solid unweathered rock lying beneath surface deposits of
soil
2: principles from which other truths can be derived; "first
you must learn the fundamentals"; "let's get down to
basics" [syn: fundamentals, basics, fundamental
principle, basic principle]