第一次用 Ubuntu,用 gcc 编译错误，打印出这个是什么原因？

/usr/bin/ld: /tmp/ccZVxb15.o: in function `__static_initialization_and_destruction_0(int, int)':
t.cpp:(.text+0x49): undefined reference to `std::ios_base::Init::Init()'
/usr/bin/ld: t.cpp:(.text+0x5e): undefined reference to `std::ios_base::Init::~Init()'
collect2: error: ld returned 1 exit status

源代码是这样的

///
#include<stdio.h>
using namespace std;
int main()
{
   // cout<<"Hello World";
   printf("Hello World");
    return 0;
}