ThroughoutJuly1945，theJapanesemainland，fromTokyoonHonshunorthwardtothecoastofHokkaido，werebombedasifaninvasionwereabouttotakeplace．Infact，somethingfarmorethreateningwasathand，astheAmericansweretellingStalinatPotsdam．（伯茨坦）

In1939physicistsintheUnitedStateshadlearnedofexperimentsinGermanyshowingthepossibilityofatomicpowerandunderstoodthecomingdamageofanatomicbomb．OnAugust2，1939，AlbertEinsteinwarnedPresidentRooseveltofthedangerofNaziGermany'sadvancesindevelopmentoftheatomicbomb．Eventually，theU．S．OfficeofScientificResearchDevelopmentwascreatedinJune1941andgivencombinedresponsibilitywiththeWarDepartmentintheManhattanProjecttodevelopanuclearbomb．Afterfouryearsofresearchanddevelopmentefforts，anatomicdevicewassetoffonJuly16，1945，inadesertareaatAlamogordo，NewMexico，producinganexplosivepowerequaltothatofmorethan15，000tonsofTNT．Thus，theatomicbombwasborn．Truman，thenewU．S．president，believedthatthisterribleobjectmightbeusedtodefeatJapaninawaylesscostlyofU．S．livesthananordinaryinvasionoftheJapanesehomeland．Japan'sunsatisfactoryreplytotheAllies'PotsdamDeclarationdecidedthematter．

OnAugust6，1945，anatomicbomb，carriedfromTinianIslandintheMarianainaspeciallyequippedB-29wasdroppedonHiroshima，atthesouthernendofHonshu．Thecombinedheatandexplosiondestroyedeverythingintheexplosion'simmediateneighbourhood，producedfiresthatburnedoutalmost4.4squaremilescompletely，andkilledbetween70，000and80，000people，inadditiontoinjuringmorethan70，000others．AsecondbombdroppedonNagasakionAugust9，killedbetween35，000and40，000people，injuredalikenumberandruined1.8squaremiles．

9．Whatisthemainideaofthepassage？___

A．AnatomicbombwasdroppedonHiroshimaandNagasaki．

B．Afterresearchanddevelopmentefforts，anatomicbomb was born．

C．Aninvasionwasabouttotakeplacewiththeuseoftheatomicbomb．

D．ThebirthanduseoftheatomicbombendedtheSecondWorldWar．

10．AlbertEinsteinwarnedRooseveltof___．

A．NaziGermany'success in making anatomicbomb

B．the possib