没有变化格式么?则以下变化均可：
Why did you fail the science exam again?
= Why did you fail in the science exam again?
= Why did you fail to pass the science exam again?
= Why did you not pass the science exam again?
= Why didn't you pass the science exam again?
也可以把why换写成For what或What...for?(for放在句尾)；
again也可以换写成once more等.