单项选择题
A.int operator-(FunNumbe); B.FunNumber operator-(); C.FunNumber operator-(int); D.int operator-(FunNumber,FunNumber);
A.f.get(c)与t.put(c) B.f.put(c)与t.get(c) C.t.get(c)与f.put(c) D.t.put(c)与f.get(c)