that they're built for a life on the move. 预示着它们一生都将奔波在路上

25. Their herd will soon be moving on,
    羚羊群很快就要离开
26. seeking the freshest new grass.
    去寻找最新鲜的草场
27. Their lanky legs are a sure sign
    高鼻羚羊四肢瘦长
28. that they're built for a life on the move.
    预示着它们一生都将奔波在路上
29. Saiga always give birth to twins,
    高鼻羚羊总会产下孪生幼崽
30. so their numbers grow rapidly just when grass is plentiful.
    这样能够在草源充足时迅速繁衍
31. Their bizarrely shaped nose can detect fresh growth
    它们的鼻子长相奇怪 却能够勘测到

来自《行星地球 第二季 第五集 Planet Earth S02E05 草原》第 28 行