pack ice zone

例句：

1. 1.The polar ice zone is a region where the sea freezes over during winter.
   极地冰区是冬季海水结冰的地区。
2. 2.The pack ice zone is one of the most dangerous areas for marine life.
   北极冰带是海洋生物最危险的区域之一。
3. 3.The scientists are studying the movement of pack ice in the Arctic Ocean.
   科学家们正在研究北极洋中冰层的移动情况。