in this dangerous world of ice. 要保护好自己的幼仔 母熊必须施展出所有的本领

186. Two weeks later, they are ready.
     两周后它们做好了准备
187. 0ut on the sea ice, the female can hunt for seals
     雌熊有可能在海冰上捕食到海豹
188. but it will take all her mothering skills to keep her cubs safe
     但是这个冰雪世界危机四伏
189. in this dangerous world of ice.
     要保护好自己的幼仔 母熊必须施展出所有的本领
190. The annual melt has begun.
     每年一次的解冻期来了
191. This is a challenging time for the bear family.
     对于北极熊一家来说 这是一个极富挑战性的时刻
192. 0ne out of every two cubs do not survive their first year out on the ice.
     两只幼熊中往往会有一只无法在第一年存活下来

来自《行星地球 第一季 第六集 Planet Earth S01E06 冰雪世界》第 189 行