Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient world slept only 6.5 hours a night.

Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient ...

根据我们对中华白海豚的追踪，它们也有类似的社会文化。例如开头提到的，母豚背负、悼念幼崽时，同村的其他个体也会接替背负；李氏和林氏的互不往来，可能也是这两个村落的社会文化。海豚之间的关联，能够影响遗传结构、疾病传播、个体适应性等多方面，研究它们的社会关 ...

如 endangered、threatened、mammal、habitat 等。 语法：学习现在进行时的被动语态，即 “am/is/are being + 过去分词”，强调此时此刻正在进行的被动动作 ...