So far, Earth has endured five of these apocalyptic events, 到目前为止 地球已经经历了五次这样的末日事件
Only when life is so bountiful can females afford to be so choosy. 只有在生活如此富饶时 雌性才能如此挑剔
So when the Ice Age hit two and a half million years ago, 所以 2500万年前 当冰河时代突然袭来之时
so she can judge their strength and stamina. 以便雌鲸能够评估自己的力量和耐力
The young Doedicurus is so much smaller. 巨犰狳幼崽小得多