Approximate • Average • Blankets • British • Btus • Built • Chemical • Circulate • Common • Commonly • Convert • Due • Easier • Effect • Ethanol • Fuel • Gallons • Generate • Heating • Include • Into • Main • Natural • Near • Placing • Pleasant • Portability • Produce • Produces • Proper • Provide • Purify • Ranging • Reaction • Reactions • Require • Safety • Should • Source • Sources • Taken • Type • Unattended • Underwater • Units • Use • Ventilation • Volts • Weight • Wilderness