The limestone towers of Vietnam's Ha Long Bay 越南下龙湾的石林

45. Limestone is composed of minerals derived from marine shells and corals,
    石灰岩由海螺和 珊瑚中的矿物沉积后形成
46. so although this rocky escarpment in the United States is now hundreds of metres above sea level
    所以 尽管美国境内的这座石壁 如今矗立在海平面以上几百米高的地方
47. it was actually formed under water.
    它实际上却是在水下形成的
48. The limestone towers of Vietnam's Ha Long Bay
    越南下龙湾的石林
49. are a reminder of this link with the sea.
    能说明石灰岩与海洋的关系
50. Originally, this whole area would have been one solid block of limestone,
    起初 这整个地方都是 一整块坚固的石灰岩床
51. the base of a coral reef.
    珊瑚礁的基座

来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 48 行