Being in a foreign country, _______.

A．one may soon change his old habits

B．one’s old habits will soon be changed

C．there’ll be some change in his habits

D．one’s new habits will soon be formed

有以下函数： fun(char * a，char * b) { while((*a!='\0')&&(*b!='\0')&&(*a==*b)) { a++；b++；} return(* a-*b)； } 该函数的功能是______。

A．计算a和b所指字符串的长度之差

B．将b所指字符串连接到a所指字符串中

C．将b所指字符串连接到a所指字符串后面

D．比较a和b所指字符串的大小