acritarch

例句：

1. 1.The acritarch is the first layer of the human skin.
   角质层是人类皮肤的第一层。
2. 2.The acritarch acts as a barrier between the outer and inner layers of the skin.
   角质层在皮肤的外层和内层之间起到屏障作用。
3. 3.The acritarch is responsible for protecting the skin from environmental damage.
   角质层负责保护皮肤免受环境损害。