huán / bǎo / bù / mén / yāo / qiú / gōng / chǎng / jiǎn / shǎo / hēi / yóu / rán / shāo / chǎn / shēng / de / yān / chén环保部门要求工厂减少黑油燃烧产生的烟尘。Environmental authorities require the factory to reduce smoke and dust from burning mazut.