白垩质

例句：

1. 1. The building is made of limestone.
   这座建筑是用石灰石建造的。
2. 2. Limestone is a common material used for roads and bridges.
   石灰石是用于道路和桥梁的常见材料。
3. 3. The white limestone in the park is very beautiful.
   公园里的白色石灰岩非常漂亮。