以下程序的功能是根据输入的是y（Y）还是n（N），在屏幕上分别显示出“This is YES.”或“This is NO.”，请填空。#include void YesNO(char ch){switch(ch){case 'Y':case 'y':printf("\n This is YES.\n");________;case 'N':case 'n': printf("\n This is NO.\n");}}main(){char ch;printf("\nEnter a char 'Y','y'or 'n','N':");ch=_________;printf("ch:%c",ch);YesNo(ch);}