The crocodile's jaws snap tight like a steel trap - 鳄鱼的巨口像捕兽铗一般紧咬住猎物

111. giants that grow over five metres long.
     这些大怪物能长到5米多长
112. From memory, the wildebeest are coming
     鳄鱼凭着记忆得知 角马已经来了
113. and gather in anticipation.
     不出所料 它们纷纷下水
114. The crocodile's jaws snap tight like a steel trap -
     鳄鱼的巨口像捕兽铗一般紧咬住猎物
115. once they have a hold, they never let go.
     一旦被它逮住 猎物再无逃脱的机会
116. It took over an hour to drown this full-grown bull.
     它得花上一个多小时 才能淹死这只成年公角马
117. To surprise their prey
     为了突袭猎物

来自《行星地球 第一季 第三集 Planet Earth S01E03 淡水》第 114 行