but nutrients alone can not support life. 但只有养分并不能维持生命
And on this reef the snakes do not hunt alone. 在这个珊瑚礁里,海蛇并不是单独行动
The East African savannahs alone sustain nearly two million wildebeest. 仅生活在东非稀树大草原的角马 就接近两百万(注:角马属羚羊的一种)
Most of their lives are now spent alone, 它们一生的大部分时间都独来独往
Abandoned by the sun, the males are left alone with their eggs 太阳已经完全消失,雄企鹅们与它们的蛋相依为命
There are 850 different cichlids alone, 这里有850多种不同的慈鲷