pretophaceous

例句：

1. 1. The pretophaceous layeris the first layer of soil that formson the surface of the earth.
   预成土层是地球表面形成的第一层土壤。
2. 2. The pretophaceous layerplays a crucial role in the growth anddevelopment of plants.
   预成土层在植物的生长和发育中起着至关重要的作用。
3. 3.The pretophaceous layer helpsto retain moisture and prevent erosion.
   预成土层有助于保持水分并防止侵蚀。