我把程序编译了，但是出现了5个错误呢？

U:\C++\renyi\ren.cpp(36) : error C2248: 'x' : cannot access protected member declared in class 'Point'
U:\C++\renyi\ren.cpp(1 : see declaration of 'x'
U:\C++\renyi\ren.cpp(36) : error C2248: 'y' : cannot access protected member declared in class 'Point'
U:\C++\renyi\ren.cpp(1 : see declaration of 'y'
U:\C++\renyi\ren.cpp(36) : error C2248: 'z' : cannot access protected member declared in class 'Point'
U:\C++\renyi\ren.cpp(1 : see declaration of 'z'
U:\C++\renyi\ren.cpp(52) : error C2374: 'i' : redefinition; multiple initialization
U:\C++\renyi\ren.cpp(4 : see declaration of 'i'
U:\C++\renyi\ren.cpp(53) : error C2593: 'operator <<' is ambiguous
Error executing cl.exe.

renyi.exe - 5 error, 0 warning

怎麽办呢？