【GCC version can not be changed】

[夏晗]

root@Xia-Ubuntu:/usr/bin# gcc -v
使用内建 specs。
COLLECT_GCC=gcc
目标：x86_64-pc-linux-gnu
配置为：../configure -enable-checking=release -enable-languages=c,c++ 
-disable-multilib
线程模型：posix
gcc 版本 6.2.0 (GCC) 
I have tried many methods like 'ln' and priority changing, but 'gcc -v' still 
maintain at '6.2.0'.......