你经历过你不舒服，你必须检查它配备了烟管流动凡通风风扇罩无法访问或曾在密闭空间在哪里？

Have you ever experienced you were uncomfortable when you had to check air flow with a smoke tube where ventilation fan or hood was unreachable or was located at confined space?

youdao

你经历过你不舒服，你必须检查它配备了烟管流动凡通风风扇罩无法访问或曾在密闭空间在哪里？

Have you ever experienced you were uncomfortable when you had to check air flow with a smoke tube where ventilation fan or hood was unreachable or was located at confined space?

youdao