once they have a hold, they never let go. 一旦被它逮住 猎物再无逃脱的机会
It was once considered a kind of raccoon, 它曾经被认为是浣熊的一种
These spires are the eroded remains of an ancient seabed that once stretched between the two continents. 曾经连接两块大陆的古老海床 侵蚀后留下了一座座尖耸的山峰
the sun once more rises over Antarctica. 太阳重新在南极上空升起
A pack this size kills once a day and everything is shared. 这种规模的狗群每天都得进行一次捕杀 并且一起分享猎物
Once the seals have finished breeding 等到海豹结束繁殖