Составьте предложения

1. the most, and, chlorine, is, most, of, common, the halogens, important.
2. the atmosphere, the richer, oxygen, is, in, combustion, the quicker, occur, may, process.
3. is, the speed, the second, of, factor, burning, the flammability, determining, the material, of.
4. are, of, class B, a liquid, fires, or, fires, solid, a liquefiable.