scanning the ground beneath for signs of prey. 搜寻地上猎物的踪迹

11. The Central Asian Steppe alone
    仅中亚的疏树大草原
12. extends one third of the way around our planet.
    便横跨了地球的三分之一
13. It's summer, and eagles effortlessly cruise the thermals,
    在夏天 雄鹰可以毫不费力的在热气流上盘旋
14. scanning the ground beneath for signs of prey.
    搜寻地上猎物的踪迹
15. In the distant reaches of outer Mongolia,
    在遥远的外蒙古大草原
16. one of the planet's great migrations is underway.
    地球上规模最大的迁徙大军正浩浩荡荡地行进着
17. Few people ever see this extraordinary annual event.
    这一蔚为壮观的场面一年一次 但却很少有人亲眼目睹

来自《行星地球 第一季 第七集 Planet Earth S01E07 伟大草原》第 14 行