单项选择题A.raceB.paceC.speedD.step
单项选择题A.lastB.givenC.fixedD.definite
单项选择题A.spendingB.demandingC.consumingD.saving
单项选择题A.portionB.percentageC.proportionD.fraction
单项选择题A.BecauseB.WhileC.SinceD.When