Question

【题目】The math problem is so hard． I really don't know________.
A.how to do it
B.how to do
C.what to do it
D.where to do it

Answer 1

【答案】A
【解析】句意：这道数学题太难了。我真的不知道怎么做这道题。how怎样；what什么；where哪里。根据句意排除C和D；how是疑问副词，不可作do的宾语，后面应加宾语it，为how to do it；而what是疑问代词，可以直接作do的宾语，故为what to do。故选A。