鳍状肢

例句：

1. 1. The fish swims gracefully through the water with its long, slender tail.
   这条鱼游动时，长而纤细的尾巴显得非常优雅。
2. 2. The frog leaps across the pond with its powerful hind legs and four short front legs.
   青蛙用它强壮的后腿和四只短的前腿跳过池塘。
3. 3. The dolphin uses its unique flippers to propel itself through the water.
   海豚使用其独特的鳍来推动自己在水中前进。