There are few known fossil specimens of these ancient snakes and only three in which the hind limbs are preserved and visible.(这些古老蛇类的化石标本非常稀少，仅有的三个标本的后肢保存完好并可见。)
Their streamlined bodies, the absence of hind legs, and the presence of a fluke and blowhole cannot disguise their affinities with land dwelling mammals.(它们的身体呈流线型，后肢完全消失，身体上长出了尾片和喷水孔，所有这些特征都无法掩饰它们与陆生哺乳动物之间的亲缘关系。)
Moreover, walruses and seals drive themselves through the water with thrusts of their hind flippers, but sea lions use their front flippers.(此外，海象和海豹用它们的后鳍推动自己在水中运动，而海狮用它们的前鳍。)
The first wrongly assumes that the pterosaurs' hind feet resembled a bat's and could serve as hooks by which the animal could hang in preparation for flight.(第一个（假设）错误地认为翼龙的后脚类似于蝙蝠的后脚，可以作为钩子，用来挂起来准备飞行。)
The large hind legs were used for propulsion in water.(巨大的后肢用于在水中驱动。)
The glands on its hind feet can secrete poisonous fluid.(它后脚上的腺体能分泌出毒液来。)
He collects cans, crisp packets, and plastic bottles from parks near his home before jumping up onto his hind legs to place them into bins.(他在家附近的公园中收集易拉罐、零食袋以及塑料瓶，然后跳起来用后腿把它们扔到垃圾桶中。)
One big mottled arm shot out and caught Toad by a fore-leg, while the other-gripped him fast by a hind-leg.(一只长斑点的大胳膊猛地伸出来，抓住托德的一条前腿，另一只手抓住他的一条后腿。)
Suddenly the cow kicked up its hind legs.(突然奶牛踢起了后腿。)
A magnificent Poodle appeared, walking on his hind legs just like a man.(一只华丽的鬈毛狗出现了，像人一样用后腿走路。)
