1. 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。
2. 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。
3. 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。
4. Paris street urchins used to shoot fancy people with rocks as they rode their carriages through the muddy streets of Paris. 巴黎的顽童们过去经常用他们的弹弓“袭击”那些驾着马车穿过巴黎泥泞街道的人们。
5. The bright red color of a fire urchin warns predators that its spines are poisonous. Sea otters are the major predators of sea urchins. 火海胆鲜红的颜色警告捕食者它的刺有毒。海獭是海胆的主要捕食者。
