Pickings are usually thin for the salamanders, 大鲵的收获通常都比较少
Usually, these mountain streams only provide enough food for small animals to survive. 通常 山涧提供的食物 只能维持小型动物生存
Pumas are usually solitary and secretive. 美洲狮通常独来独往 隐秘莫测
These rare creatures are usually very shy 这种罕见的动物通常很胆小