by detecting distortions in the electric field they create around their bodies. 它们在身体周围形成电场 并感知其变化
once they have a hold, they never let go. 一旦被它逮住 猎物再无逃脱的机会
Now they are carrying heavy loads of sediment 河流中带着大量的泥沙
they gradually warm and begin to support more life. 河水渐渐变暖 养育的动物也多了起来
Living up to 80 years they grow into giants. 它们能活80多年 因此长得十分巨大
At last they are over the highest barrier that lies in their way. 最后它们终于翻越了旅途中最高的障碍
they use thermals, rising columns of warm air, to gain height. 可它们会利用热空气 ——呈圆柱形上升的热气流来获取高度