英语听力：从南极到北极 3

But they are hungry and eager to reach their mother who’s delayed feeding them on this special day. Now she lures them with the promise of milk, the only food the cubs have known since they were born, deaf and blind beneath the snow some two months ago. Their mother has not eaten for five months and has lost half her body weight. Now she converts the last of her fat reserves into milk for her cubs.

The spring sun brings warmth, but also a problem for the mother. It starts to melt the sea ice. That is where she hunts for the seal she needs to feed her cubs and she must get there before the ice breaks up. For now though, it’s still minus 30 degrees and the cubs must have the shelter of theden.

It’s six days since the bears emerged and spring is advancing rapidly. But even now, blizzards can strike without warning. Being so small, the cubs are easily chilled and they will be more comfortable resting in the den. But their mother must keep them out and active. She’s becoming weak from hunger and there’s no food on these nursery slopes. The sea ice still holds firm, but it won’t last much longer.