正确答案原因上面说的很清楚,我写几个自己改的句子吧
如果用what,句子就不是这样了,后面一半要加具体的物而不是单纯引导定语从句了
Have you ever asked him to explain what's the reason that he's absent?
用why
Have you ever asked him the reason why he's absent?
when在这里实在不靠谱,就不谈了
可以看出其实句子到have you asked him the reason结构已经完整了,后面只是补充说明说法很多,但是是由具体语序导致的成分变化决定的答案
希望能给你帮助