多条printf输出
调用一次printf函数，实现多条语句输出。
Source:#include<stdio.h>
void main()
{
printf("How are you!\nWelcome to the c language world!\nEveryone has been waiting for.\n");
}
#include<stdio.h>
void main()
{
printf("How are you!\nWelcome to the c language world!\nEveryone has been waiting for.\n");
}