dirty coal

例句：

1. 1. The dirty coal mine is a dangerous place to work.
   这个脏煤矿是一个危险的工作场所。
2. 2. The dirty coal mine has been closed due to safety concerns.
   由于安全担忧，这个脏煤矿已经被关闭了。
3. 3. The dirty coal mine has caused many environmental problems.
   这个脏煤矿已经造成了许多环境问题。