underground coal mining district的意思|示意
美 / /
英 / /
井下采煤区
underground coal mining district的网络常见释义
井下采煤区 underground coal gasification ==> 煤地下气化,煤炭地下气化 underground coal mining district ==> 井下采煤区,井下采煤区 underground collector ==> 地下接触轨集电器 ..