mixture, air, oil, injection, rocket, rockets, plants, wood, combustion, vehicles, engines, economy, engine, consumption, minerals, cycle, pump, use, energy, efficiency, mixtures, motor, burning, missiles, burners, ratio, gas, storage, missile, flow, charge, ash, cell, handling, reserves, switching, substitution, tanks, elements, firing, cells, plant, boilers, costs, vehicle, commodities, operation, taxes, tank, motors, food, reactor, rod, tax, feed, supplies, oxygen, stoves, flame, cars, delivery, furnaces, booster, supply, prices, mix, adjustment, gauge, metering, cutting, gathering, industries, competition, boosters, filter, generation, fabrication, stations, deposits, conservation, transfer, capacity, assemblies, steam, reduction

more, nuclear, fossil, liquid, solid, enough, spent, less, fresh, much, only, cheap, gaseous, additional, domestic, extra, sufficient, primary, alternative, clean, excellent, unburned, octane, excess, dry, synthetic, available, principal, auxiliary, necessary, industrial, conventional, residual, precious, diesel, heavy, expensive, grade, ideal, preferred, unleaded, valuable, cheaper, atomic, abundant, standard, volatile, irradiated, commercial, suitable, derived, raw, automotive, chief, mixed, dual, leaded, combustible, efficient, insufficient, non, adequate, supplemental, unburnt, based, wet, cheapest, ample, supplementary, locomotive