【C12】A．basesB．factorsC．causesD．fractions

He has found a lot of reasons to explain his failure.A.effectsB.resultsC.causesD.bases

【C7】A．providesB．witnessesC．causesD．holds

【C3】A．generationsB．descentsC．causesD．origins

A．plan B．fraction C．main D．framework

58._________A. improvements B. factorsC. jobsD. m

下列是重载为非成员函数的运算符函数原型 其中错误的是( )。A.Fractionoperator+(Fraction Fract