maximum allowable thickness of barren rock

例句：

1. 1. The maximumallowable thickness of the barren rockis 20 cm.
   该贫瘠岩石的最大允许厚度为20厘米。
2. 2.The construction company has to adhere to themaximum allowable thickness of the barrenrock.
   建筑公司必须遵守贫瘠岩石的最大允许厚度。
3. 3. The engineer carefully measured themaximum allowable thickness of the barrenrock before starting the project.
   工程师在开始项目之前仔细测量了贫瘠岩石的最大允许厚度。