TheextraordinaryEastgateBuildinginHarare，Zimbabwe'scapitalcity，issaidtobetheonlyoneintheworldtousethesamecoolingandheatingprinciplesasthetermitemound（白蚁堆）．ArchitectMickPearceusedpreciselythesamestrat
TheextraordinaryEastgateBuildinginHarare，Zimbabwe'scapitalcity，issaidtobetheonlyoneintheworldtousethesamecoolingandheatingprinciplesasthetermitemound（白蚁堆）．
ArchitectMickPearceusedpreciselythesamestrategywhendesigningtheEastgateBuilding，whichhasnoair-conditioningandalmostnoheating．Thebuilding-thecountry'slargestcommercialandshoppingcomplex-useslessthan10% oftheenergyofaconventionalbuildingofitssize．TheEastgate'sownerssaved3.5millionona36millionbuildingbecauseanair-conditioningequipmentdidn'thavetobeimported．
Thecomplexisactuallytwobuildingslinkedbybridgesacrossashady，glass-roofedatrium（天井） opentotheair．Fanssuckfreshairinfromtheatrium，blowitupstairsthroughhollowspacesunderthefloorsandfromthereintoeachofficethroughbaseboardvents（通风口）．As it risesandwarms，itisdrawnoutviaceilingventsandfinallyexiststhroughforty-eightbrickchimneys．
Duringsummer'scoolnights，bigfansblowairthroughthebuildingseventimesanhourtocooltheemptyfloors．Byday，smallerfansblowtwochangesofairanhourthroughthebuilding，tocirculatetheairwhichhasbeenincontactwiththecoolfloors．Forwinterdays，therearesmallheatersinthevents．
ThisisallpossibleonlybecauseHararei1600feetabovesealevel，hascloudlessskies，littledampnessandrapidtemperaturechanges-daysaswarmas31℃commonlydropto14℃atnight．"Youcouldn'tdothisinNewYork，withitshotsummersandcoldwinters，"Pearcesaid．
TheengineeringfirmofOveArup&Partnersmonitorsdailytemperatures．Itisfoundthatthetemperatureofthebuildinghasgenerallystayedetween23℃and25℃，withtheexceptionoftheannualhotperiodjustbeforethesummerrainsinOctoberandthreedaysinNovember，whenadoorkeeperaccidentallyswitchedoffthefansatnight．Andtheairisfresh-farmoresothaninair-conditionedbuildings，whereupto30% oftheairisrecycled．
29．WhywasEastgatecheapertobebuiltthanaconventionalbuilding？___
A．Itwasdesignedinasmallersize．
B．Noairconditionerswerefixedin．
C．Itsheatingsystemwaslessadvanced．
D．Itusedratherdifferentbuildingmater