The protection and recovery of ecological environment after exploited thecoal mine is an important problem.

矿区开发后生态环境的保护和恢复是一个重要问题。

youdao

The protection and recovery of ecological environment after exploited thecoal mine is an important problem.

矿区开发后生态环境的保护和恢复是一个重要问题。

youdao