7. Определите значение выделенных слов, по сходству их корней с корнями соответствующих слов в русском языке:

natural gas, petroleum products, chemical processes, gaseous fuel, energy carries, aviation turbine, the different categories of solid fuels, the basis of practically all natural fuels, the small amount of other elements, to be associated with water and gas, light machine oil, motor oil, useful industrial materials, certain types of electrodes, aromatic petrochemicals, polymer material, can be used as plastics.