weak rock

例句：

1. 1. The weak rock crumbled underthe weight of the heavy rain.
   这弱岩在大雨的重量下崩塌了。
2. 2. Thebuilders used this type of weak rockfor the foundation of the new building.
   建筑工人用这种弱岩作为新建筑的基础。
3. 3. The weak rock was too fragile tosupport the weight of the heavy equipment.
   这弱岩太脆弱，无法承受重型设备的重压。