and not enough of their energy reaches the ground to enable trees to grow. 到达地面的能量很少 并不足以支持树木生长
and now it's easier to target an individual. 狼群便更容易锁定单个目标
Newborn calves have to be up and running the day they are born. 新生的小鹿必须 在出生的第一天就站起来奔跑
and the thawing shifting landscape. 融化的冰雪不断改变着地貌
and the mother has led her cubs a mile from the den. 母熊已经带领幼熊离巢1英里远
But their mother must keep them out and active. 可是母熊必须得把它们带到外边活动