layer/ˈleɪə(r)/
n.1. 层There is a layer of dust on the dressing-table. Clean it before the guest arrives.梳妆台上盖着一层灰尘，在客人来之前，把它擦干净。
a layer of clay黏土层
This cake has a layer of chocolate in the middle.这蛋糕中间有一层巧克力。
If there had not been a hard layer of rock beneath the soil, they would have completed the job in a few hours.如果土壤下面没有坚硬的岩层，他们早就在几个小时内完成这项工作了。
2. 蛋禽；产卵鸡3. 〈植〉压条