As it builds up 随着它的积累

142. and when it meets the air in the cave
     当它与洞内空气接触时
143. some of that is deposited as a mineral -
     其中的一些就会沉淀为一种矿物
144. calcite.
     方解石
145. As it builds up
     随着它的积累
146. so the calcite forms decorations that hang from the ceiling -
     方解石形成了悬在洞顶上的装饰物
147. stalactites.
     钟乳石
148. Each drop leaves behind only a miniscule amount of calcite,
     每滴水珠只会留下极少量的方解石微粒

来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 145 行