潜水用橡皮制鳍状肢

例句：

1. 1. The fish has afin on each side of its body.
   这条鱼身体两侧各有一根鳍。
2. 2. Thedolphin has a long finthat helps it swim.
   海豚有一条长长的鳍，帮助它游泳。
3. 3. The shark has manysharp teeth and a long fin.
   鲨鱼有许多锋利的牙齿和一条长鳍。