The math problem is so hard, I really don’t know ____

试题详情及答案解析

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．when to do

答案：A

试题分析: 句意：---数学题如此难，我真的不知道怎么做它。此题考查宾语从句和不定式之间的转换，根据句意，故选A。
考点：考查疑问词+动词不定式。