manganese concretion的用法和樣例：
例句
- But despite millions of dollars of investment, the commercial extraction of manganese nodules never became reality.
但是儘管擁有數百萬美元的投資，錳結核的商業化開採始終未能實現。 - Unlike manganese nodules, which are like golf balls scattered across the sea bed, these deep-ocean deposits occur in small areas around extinct hydrothermal vents.
與錳結核像高爾夫球洞一樣分散在海底不同的是，這些深海礦物層則在熄滅了的海底煙囪附近小範圍內存在。
