以下程序的功能是根据输入的“y”(“Y”)与“n”(“N”),在屏幕上分别显示出“This is YES.”与“This is NO.”。请填空。 void YesNo(char ch) { switch(ch) { case ‘y’: case ‘Y’: printf(“\nThis is YES.\n”); _________; case ‘n’: case ‘N’: printf(“\nThis is No.\n”); } } int main() { char ch; printf(“Enter a char ‘y’,‘Y’or‘n’,‘N’:”); ch=____________; printf(“ch:%c”,ch); YesNo(ch); }