Unit2FoodHoodiaATheSanliveinthatpartofAfricacalledtheKalahari[ka:la:´ha:ri]Desert.（喀拉哈里沙漠，非洲南部)Lifethereishard,andnaturecanbeharsh[ha:ʃ](严厉的).Therearesomewherebetween45,000and100,000ofthemlivingincountrieslikeZambia[´zæmbiə]（赞比亚，非洲中南部）andZimbabwe[zim´ba:bwei]（津巴布韦，非洲）.They’renotrichandtheydon’tliveinexpensivehouses.Therearenoroadsorschoolsorhospitalsnearthem.Theydon’thavemanymaterialpossessions[pə´zeʃənz]（财产）likecarsorcomputers,thingsthatpeopleinthedevelopedworldcan’tdowithout.Infact,theyhavemanyproblemssuchasunemploymentandpoverty（贫困）.Onthetopofthis,theyalsosufferfromalcoholism[´ælkəhɔlizəm]（酗酒）,drinkingtoforgettheirproblems.They‘retheSan,atribeoftraditionalhunter-gatherers,whousedtotravelinsearchoffoodfortheirfamiliesinsteadofgrowingitorkeepinganimals.Theyhaveaculturethatis20,000yearsold,buttheiroldwayoflifeisdisappearingfastandhasnearlygoneforever.Soyes,they’repoor,andyes,theirlifestyleisnotattractivetooutsiders,buttheydohaveonethingthatcertainpeopleinthedevelopedworldareveryveryinterestedinandwanttohave,andthatmaymakethemsomemoney.It’scalledhoodia（仙人掌）.BManycountrieshavebasic,commoncropsthatpeopleplantforfood,suchasriceorpotatoes.PotatoesaregrowninmanyEuropeancountriesaswellasSouthAmerica(Theyoriginatedthere!),andriceisastaple[´stepl]food（主食）inAsia.Butnotallplantsaregrownjustforfood;someofthemcanalsobeusedasmedicine.Afewexamplesaregarlic（大蒜）,whichissaidtohelpwithcoldsorhighbloodpressure,ginger（姜）tohelpwithheadachesortoothache,orthemagnolia[mæg´nauliə]（木兰）treewhichisusedinChinesetraditionalmedicinetotreatsomeformsofcancerandheartdisease.Hoodia,acactus[´kæktəs]（仙人掌）-likeplant,onlygrowsintheareawheretheSanlive,andtheyknowwheretofinditandthebesttimetouseit.Theyhaveknownaboutitforcenturiesandtheyunderstandhowtouseit,buttheydon’tuseitforfood,andtheydon’tuseittocurediseaseeither.Theyuseittofighthunger.CIntheolddayswhentheSanhadtotravelinsearchoffood,theyandtheirchildrensometimeshadtogowithoutfoodforseveraldays.Thiswasevenlongerintimesoffamine[´fæmin]（饥荒）orwhentherainsfailed.Theyatethehoodiaplantwhentheywerestarving,tohelpthemsurviveuntiltheyfoundfood,tostoptheirchildrenfromcrying,andtogivethemthestrengthtocontinuetheirsearch.However,itdidn’tgivethemenergylikenormalfoodwould.Instead,thechemicalsinthehoodiaplantkilledthefeelingofhungerandstoppedthemwantingfood.Theydidn’tknowexactlyhowitworked;theonlythingtheyknewforcertainwasitdidwork.DScientistshavenowdiscoveredthattheplantcontainsasubstance[´sʌbstəns]（物质）whichtheyhavecalledP57.Thischemicalmakesthebrainbelievethatthestomachisfullandthatthebodydoesn’tneedfood.Thatiswhypeopleinthedevelopedworld,especiallythoseinpharmaceutical[,fa:məsu:tikl]（制药的）companies,areextremelyinterestedinthisverypromising（有前途的）plant.EObesity[əu´bi:siti]（肥胖）inthedevelopedworldisahugeandgrowingproblem,notonlyamongadults,butincreasinglyamongchildren.Ithasbeenestimated（估计）thatupto50%ofpeopleinthedevelopedworldareoverweightand20%oftheseareobese;atthetimeofwriting,forexample,30%ofChinesechildrenwereconsideredtobetooheavyfortheirage.Onecauseofobesityiseatingthewrongkindoffood.Ourgrandparentshadthetimetopreparesimpleyetnourishing[´nʌriʃiŋ]（有营养的）meals,andtheydidn’teatasmuchmeatorfattyfoodsaswedonowadays,andthat...
