diplopy

例句：

1. 1. Diplodocus wasa type of ancient reptile that livedduring the Cretaceous period.
   双足龙是一种生活在白垩纪时期的古代爬行动物。
2. 2. The dinosaurs were bipedal creatures that walkedon two legs.
   恐龙是两足行走的生物。
3. 3. Quadrupeds areanimals that have four legs and walk ontwo feet at a time.
   四足动物是指那些有四条腿，一次用两只脚走路的动物。