—Has your father finished his report?

—Sorry，I don’t know．He ________ it this morning．

A．was writing

B．wrote

C．has written

D．had written

下列关于运算符重载不正确的是( )。

A．运算符重载不能改变运算符的操作数个数
B．运算符重载不能改变运算符的优先级
C．运算符重载不能改变运算符的结合性
D．运算符重载能改变对预定义类型数据的操作方式