The oceanic crust lies beneath the ocean floor and has a thickness of five to twelve kilometers. On the upper surface, there is a thin layer of unconsolidated sediment that rests on the basement layer composed of basalt.是什么意思_The oceanic crust lies beneath the ocean floor and has a thickness of five to twelve kilometers. On the upper surface, there is a thin layer of unconsolidated sediment that rests on the basement layer composed of basalt.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句