Why were you late for school this moring?--------I was ill,and had to see a doctor first.A as

问题描述:

Why were you late for school this moring?--------I was ill,and had to see a doctor first.A as
Bsince C because Dfor

C
因为前面提问的疑问代词是“why”,所以用because来作答,解释迟到的原因.