flipper-like limb bud

例句：

1. 1.The baby ducklings were swimming in the river, looking for a flipper-like limb bud to grow into.
   小鸭仔们在河里游泳，寻找一个可以长成鳍状肢芽的地方。
2. 2.The scientist discovered a flipper-like limb bud in the fossilized tree trunk, which could have been used by ancient animals.
   科学家在化石树桩上发现了一个类似鳍状肢芽的器官，古代动物可能使用过它。
3. 3. The researcher believes that this flipper-like limb bud may hold clues about the evolution of aquatic life.
   研究人员认为这个类似鳍状肢芽的器官可能隐藏着关于水生生物进化的线索。