分类：教育/科学-学习帮助
问题：单项选择71.ireallydidn'tknow________ 
71. i really didn't know ___________ wh the difficult problem.a. what to do b. how to do c. to do what d. to do how
回答：a. what to do

这利用的是疑问词+不定式做宾语，那么只有答案AB符合。我们知道表示处理；解决的意思，有2个搭配-----
 what to do with sth 
how to deal with sth 
意思相同，只是搭配不同而已