By now these bears have used up most of the fat reserves that have sustained them since the ice melted.
By now these bears have used up most of the fat reserves that have sustained them since the ice melted.
目前，北极熊已经耗尽了绝大部分的体内脂肪，自从冰层开始融化以来，它们就依靠这些脂肪维持着生命。