layers

• After the gale , there was a layer of dust on the desk .
  大风过后，桌上落了一层灰。
• There are many layers of knowledge .
  认识有许多层次。
• The epidermis forms a continuous single layer of cells .
  真皮是一个连续的单一细胞层。
• His friends came in layers .
  他的朋友来自各个阶层。
• Cage layer fatigue is a type of osteoporosis .
  笼养蛋鸡疲劳症是骨质疏松症的一种类型。
• The external layer of the skin is relatively impermeable to water .
  皮肤的外层不透水。
• Layer lime and garden clippings to make compost .
  把石灰和修剪下的枝叶分层堆积做堆肥。
• He uncovered layer on layer of hidden weariness .
  他隐藏着的厌烦一层一层地暴露出来了。
• The liquid cement will cover the slit between the layers .
  液体胶合剂会遮住两层之间的接缝。
• The inner layer of the cortex differentiates into the endodermis .
  皮层的内层分化为内皮层。