sloths

Mammoths, mastodons, massive ground sloths, woolly rhinoceros, cave bears and large flightless birds suddenly became extinct.
猛犸象、乳齿象、巨型陆地树懒、羊角犀牛、洞熊和大型飞鸟突然间灭绝了。
As stated above, if allowed to vegetate, teens can and will become human sloths.
如上所述，如果任由发展的话，她们会变成懒人。
Because sloths move so slowly, it is hard for predators to see them.
And because muscle is heavy, sloths weigh far less than other mammals their size.
另外，由于肌肉重量较大，树獭比其他同等大小的哺乳动物轻很多。
They may have gone, along with mammoths, short-headed bears, ground sloths and camels, because a comet exploded over their heads.
他们可能已经同猛犸象、短头熊、地獭和骆驼一起灭绝了。因为一颗彗星就在他们头上爆炸。
Sloths reduce this cost by maintaining a lower average body temperature than other mammals.
树獭的平均体温比其他哺乳动要低，这样就减少了能量消耗。
Bats, kangaroos, moles and sloths can swim, despite their rather strange shapes.
蝙蝠，袋鼠，鼹鼠可以游泳，但他们动作很奇特。
Many animals are illegal to own as pets, including snails, sloths, and elephants.
许多动物--包括蜗牛、树懒和象--被养做宠物是违法。
I bet the mini sloths could help you make presents every year! Right, guys?
Sloths and their relatives branched off from all other placental mammals about 100 million years ago.
树懒及其亲缘大约在一亿年前与其它的胎盘哺乳动物分道扬镳。