人烟稀少 Sparsely populated

非火源区的烟气稀释 Dilution

村庄人烟稀少 Sparsely populated villages

人烟稀少的早晨 Sparsely populated in the morning ; sparsely-populated morning

烟囱稀释因子 stack dilution factor

人烟稀少地带 thinly populated area

稀有金属烟花药剂 rare metal firework powder

人烟稀少的边远地区 remote area where few people live

一股稀薄的烟雾 wraith

人烟稀少北极地区 Sparsely Peopled Arctic Regions