I want to know next.A. what to do it B. how to do C. what to do

问题补充：

I want to know next.

A. what to do it B. how to do C. what to do

答案：

解析：what可充当宾语，故不定式后不可再加宾语，所以A.what to do it 错误，去掉it就对了，故选C。而B选项中how是副词，不可充当宾语，故不定式后应补宾语it。考点：特殊疑问词+不定式的用法