haze: implies a diffusion of smoke or dust or light vapor sufficient to blur vision but not to obstruct it: mountains rendered blue by the ~.  （diffusion分散遍布: to spread out over a large area，如the heat from the radiator (was) diffused throughout the room暖气的热量遍布整个房间）


mist: implies a suspension of water droplets, floating and slowly falling through the air, that impairs but does not cut off vision: hair damp from the ~.


fog: implies a denser suspension than a mist, with power to enshroud and to cut off vision more or less completely: visibility reduced to inches by the ~.  （enshroud完全盖住笼罩to cover something completely so that it can no longer be seen，如dispiriting clouds that enshrouded us in twilight黄昏时密云笼罩让人沮丧）

smog: applies to a haze, mist, fog made thicker and darker by the smoke and fumes of an industrial area: cast a pall of smog over the city.     （a pall of形容笼罩的一团，又如a pall of black smoke一团黑烟）


haze薄雾霾霭: 指空气中遍布的烟尘汽，使视线不清但未阻断，mist水汽: 指空气中悬浮的小水滴慢慢飘浮下沉，同样使视线不清但未阻断，fog雾: 指更浓密的水汽悬浮笼罩，几乎完全阻断视线，smog油烟: 以上三项由于工业油烟变得更浓更黑，是smoke+fog合成词变体


记忆方法: 1）首字母HMFS想成还没放手<==烟雾笼罩


2）烟雾的意思是空气可见度差的状况mean an atmospheric condition that deprives the air of its transparency.   transparent透明的