oscillating tail-fin

• 摆动尾鳍

oscillating tail-fin的用法和样例：

例句

1. The fish uses its tail fins for propulsion through the water.
   鱼靠尾鳍在水中前进。
2. The lower lobe of the deeply forked caudal fin is longer than the upper lobe.
   尾鳍深叉型，下叶比上叶长。