Soot is usually the productof the imperfect combustion of fuel.
煤烟通常是燃料不完全燃烧的产物。
2
The productofcombustion is water, is the world's most clean energy.
燃烧的产物是水，是世界上最干净的能源。
3
According to GB8624-1997 "building materials combustion performance of grading method", this product is the B1 level flame retardant materials to ensure safe and reliable.