the smoke obscuration value是什么意思？

hot creep elongation
hot creep set
the smoke obscuration value
这些英文是什么意思啊？

smoke rings in the dark He followed the doctor's advice and ------smoke. Don't you smoke until the plane __ off. smoke rose from what remained of the downtown office building A __ of smoke came out of the factory. The air is so still that the smoke is rising straight up from the fire. _____ she has opened a window, the smell of smoke is still very strong 请问谁有<smoke on the water>的歌 关于 Ice Cube、Eminem、Dr.Dre和Snoop Dogg的演唱会 Up In The Smoke 请问谁有蝎子乐队的When The Smoke Is Gong的歌词！