This is much more than about speed. 这不仅仅是速度的问题
But unlike whales, they still spend much of their time lazing on land. 但与鲸不同 它们多数时间仍懒洋洋地躺在陆地上
Flying allows animals to search much further for food... 飞行使动物能够到更远的地方觅食
The young Doedicurus is so much smaller. 巨犰狳幼崽小得多
locking up much of the planet's fresh water. 将地球上的大量淡水锁住
forests had regrown and carpeted much of the land. 森林已重新生长并覆盖大部分陆地