PartⅡReadthefollowingpassagecarefullyandthenfillineachblankwithonesuitablewordorexpressionselectedfromthelist.(15points)requisiterenderidentifyunlikelyoverapartcreatesafetyultimateexceeddeformpermanentlyapplyeval

　　PartⅡReadthefollowingpassagecarefullyandthenfillineachblankwithonesuitablewordorexpressionselectedfromthelist.(15points)

　　requisiterenderidentifyunlikelyover

　　apartcreatesafetyultimateexceed

　　deformpermanentlyapplyevaluationstrength

　　Theconceptof__________factorsisnormally__________tothe__________andconsiderationof__________ofmaterialsusedinadesign.Safetyfactorsarenormallyappliedtotheyieldstrengthofamaterialbutcanbeappliedtothe__________tensilestrength.Theyieldstressisthestressabovewhichthematerialwill____________________.Having__________theyieldstressoryieldstrength,materialsbegintocreep.Thatis,dislocationswillbe__________,andapplicationofaloadtocontinuethestressaboveyieldwillallowthematerialtoslip.__________time,itmayslipenoughtosimplycome__________.Soifamaterialisusedinaserviceenvironmentinwhichtheyieldstressisneverexceeded,itis__________itwillfailbybeingoverstressed.Ontheotherhand,largesafetyfactorscould__________adesignunworkablebecausenomaterialbe__________withthe__________strengths.