At first glance, a shark's skin may seem smooth and sleek. Upon closer inspection however, shark skin has tiny scales called denticles that can help it swim faster in the water. An adult shark has ...
一些您可能无法访问的结果已被隐去。
显示无法访问的结果一些您可能无法访问的结果已被隐去。
显示无法访问的结果
反馈