We haven't settled the problem of it is necessary for him to study abroad.A. whyB. whethe

问题补充：

We haven settled the problem of it is necessary for him to study abroad.

A. why

B. whether

C. what

D. how

答案：

A. why

(答案→)B. whether

C. what

D. how

解析：B 考察宾语从句。此处的whether是否，引导一个宾语从句作为介词of的宾语。