sand stratum

• 砂层

sand stratum的用法和样例：

例句

1. Quarternary sand stratum development, with surface run-off directly charging the underground water exists.
   第四系砂层发育，地表水对地下水有直接补给关系。
2. The resista nce decreases intensely when the slenderness ratio of the hot molding sand layer increases.
   阻力随干砂层长细比的增加而急剧减小。