adj.(人類的始祖)原人的
n.(人類的始祖)原人
Protohuman moms probably fashioned baby slings, too, they suggest, both for ease of transportation and to keep the young warm by holding them close to their bodies. 史前的母親大概也使用背帶，因為方便，而且孩子緊貼著母親容易保持體溫。
