and an ibex that has fallen to its death. 和一头摔死的羱羊
...he might be able to turn it over. 也许可以将它翻过来
For the young Doedicurus, the only option is to stay put. 对巨犰狳幼崽来说 唯一的选择是保持原地不动
the grasslands played host to the same battle... 草原上发生了同样的战斗
Desperate to defend her only calf, 迫切地想要保护自己的幼崽
others evolved to feed on the grazers. 另一些哺乳动物 则进化为以食草动物为食
But just as some mammals evolved to feed on the grass, 但在一些哺乳动物 进化成以草为食的同时
...able to walk within hours of birth... 出生后几小时就能行走
strengthened to prevent silica in the grass from wearing them out... 能够防止草中的二氧化硅磨损牙齿