下面是复数类complex的定义，其中作为友元函数重载的运算符“--”的功能是将参数对象的实部减1，然后返回对该对象的引用；请补充完整。 class complex { private: int real; int imag; public: complex(int r=0,int i=0):real(r),imag(i){} void show () { cout＜＜real＜＜(imag＜0"-":"+")＜＜imag＜＜’i’; } ______; }; complex& operator -- (complex &c) { c.real --; return c; }

China has got a good ________ for fighting against the flu with its careful and smooth organization.[ ]

A. reputation  

B. influence

C. impression  

D. knowledge