But he must resist the urge to rest. 但它必须克制住想要休息的冲动
..but now predators are out and about. 但同时捕食者也开始了活动
But not all of the brood have hatched. 然而有些雏鸟还没孵化出来
But it exists at the very limits of survival. 这里的生命时时刻刻处于危机之中
..but it highlights the new realities of filming wildlife 但这也凸显了拍摄野生动物新的实际情况