fall of ground, roof fall
fall of ground, roof fall
[水利科技英汉词典]
fall of ground, roof fall冒顶
地下硐室的顶板突然塌落的事故现象。
是什么意思,fall of ground, roof fall的解释,fall of ground, roof fall的翻译
fall of ground, roof fall
[水利科技英汉词典]
fall of ground, roof fall是什么意思,fall of ground, roof fall的解释,fall of ground, roof fall的翻译