cetacean

例句：

1. 1. Cetaceansare known for their intelligence and adaptability.
   鲸鱼以其智能和适应性而闻名。
2. 2.The humpback whale is a speciesof cetacean that can reachlengths of over 30 meters.
   座头鲸是一种鲸鱼物种，其长度可达30米以上。
3. 3. Cetaceans play an important role inthe ocean ecosystem, providing food and shelterfor other marine life.
   鲸鱼在海洋生态系统中起着重要作用，为其他海洋生物提供食物和栖息地。