I will be away for at least one year and I’d appreciate ______ from you now and then.

A．having heard

B．hearing

C．heard

D．hear

下面程序的功能是将字符串s中的每个字符按升序的规则插到数组a中，字符串a已排好序。
#include＜stdio.h＞
#include＜string.h＞
void main()
char a[20]="cehiknqtw";
char s[]="fbla";
int i,k,j;
for(k=0;s[k]!=’\0’;k++)
j=0；
while(s[k]＞=a[j]＆＆a[j]!=’\0’)
j++;
for(______)
______；
a[j]=s[k]；

puts(a);