Question

types of fuel used in the kitchen and why it was less polluting

Answer 1

LPG and CNG as they r cleaner fuel

Answer 2

                                     primary(NATURAL)             secondary(ARTIFICIAL)

solid fuel              wood,coal, peat,dung,etc..              coke,charcoal
Liquid fuel            petroleum                                    diesel,kerosene,gasoline,LPG
gaseous fuel            natural gas                                hydrogen,propane,methane
                                                                                       coal gas,water gas, CNG