unworkable coal seam

例句：

1. 1. The new design is unworkable for the current production process.
   新设计对当前的生产流程来说是不可工作的。
2. 2.The project was deemed unworkable due to lack of resources.
   由于资源不足，该项目被认为是不可工作的。
3. 3. The solution proposed by the team was considered unworkable because it would require extensive modifications.
   团队提出的解决方案被认为是不可工作的，因为它需要进行大量的修改。