Question

I don't know what to do next.改为宾语从句

Answer 1

I
don't
know
what
I
should
do
next.
what
to
do为疑问代词和不定式组成的短语，你需要把它还原成句子才算宾语从句
所以改成what
I
should
do就可以了
都是我该干什么的意思

Answer 2

I
don't
know
what
I
can
do
next
.宾语从句就是宾语是一个句子，在原先的那句话里what
to
do是宾语，所以只要把它改成句子what
I
can
do
next
就行了，