Question

(河南省2006)

--- I don't know ________ with this problem. It's too hard.

--- You can ask Mr Wang for help.

[　　]

A．which to do

B．when to do

C．what to do

D．how to do

Answer 1

答案：D
解析：

解析：本题考查动词不定式的复合结构。其结构为“疑问词＋不定式”，A、B、C三项从语法上看都正确，但根据答语可知回答的是how (怎么样) 问句。故选D。