urchins
n. 海胆（urchin 的复数）；顽童
例句
Sea urchins are perhaps best known for their armor of spines.
海胆也许最出名的是它们的刺甲。
Rock lobsters prey on sea urchins, and increased rock lobster densities coincided with significant decreases in urchins.
岩石龙虾以海胆为食，而岩石龙虾密度的增加正好与海胆数量的显著减少相吻合。
