当由疑问代词引导的宾语从句,从句的主语与主句的主语一致时改为简单句，或者疑问代词作实义及物动词的宾语时，可以用疑问代词+动词不定式结构。即：

what to do.

who to do.

which to do.

……

例句：

1.Please tell me what I should do next.改为简单句是：

Please tell me what to do next.

2.I wonder who I should ask.