n.地层，油画的底层颜色（层），下层；底层

The underlayer of the soil was hard clay, making it difficult for plants to take root.
土壤下层是坚硬的粘土，植物很难生根。
They laid a new carpet over the old underlayer to hide the stains.
他们在旧衬垫上铺了一块新地毯以遮盖污渍。
The underlayer of paint had started to peel off, revealing the original color beneath.
油漆底层开始剥落，露出了下面原有的颜色。
She applied a base coat as an underlayer before painting the intricate design.
她在绘制复杂的图案之前先涂了一层底漆作为底层。
The underlayer fabric provides extra warmth and insulation in winter coats.
冬季大衣中的衬布提供了额外的保暖和隔热效果。
The underlayer of clouds obscured the view of the mountains in the distance.
远处的山峦被云层下的薄雾遮住了视线。
The archaeologists carefully removed the upper layers to expose the underlayer with ancient artifacts.
考古学家们仔细地移除上面的几层，以便露出埋藏着古代文物的底层。
The underlayer of grasses helped prevent erosion on the hillside.
山坡上的草本植物起到了防止水土流失的作用。
The artist used a neutral-colored underlayer to ensure that the final colors would appear vibrant.
艺术家使用了中性色的底层，以确保最终的颜色鲜艳夺目。
The underlayer of ice acted as a natural sealant, preventing the lake from freezing over completely.
冰层底层起到了天然密封剂的作用，阻止湖面完全结冰。