原文:Weshouldremembertwothingsaboutthisenergysource.First,theworld’spresentandprecariousdependenceonfossilfuels—firstcoal,andthenoil—isonlyabouttwohundredyearsold.Beforethat,mostoftheenergyrequiredbyhumanbeingsforheating,cookingandindustrialpurposewassuppliedfrombiologicalsources.Bythis,wemeanmainlywood,oritsderivative,charcoal.题目:Theuseofcharcoalforcookinghasbeenacommonpracticeforhundredsofyears.
Ifyouareeatingafairlyvarieddiet,itisjustaboutimpossibletogoshortofproteins,vitaminsorminerals.Itislikelythatyouhavemorethanenoughfatsandcarbohydrates.Takeproteinsforinstance.Onaverage,weeatabouttwiceasmuchproteinasweneed.Vitaminpillsarenotlikelytohelpeither.Avarieddietwithplentyoffreshfruit,vegetablesandcerealsalongwithsomefish,eggs,meatanddairyproductswillcontainmorethanenoughvitamins.Unlessyouhavesomespecialmedicalreason,itisawasteoftimeandmoneytotakevitaminpills.Ifyourdailydietisarathervariedone,itisalmostimpossiblethat_____