I just wonder that upsets him so much.A. what it isB. what he doesC. how it isD. why it do

问题补充：

I just wonder that upsets him so much.

A. what it is

B. what he does

C. how it is

D. why it does

答案：

(答案→)A. what it is

B. what he does

C. how it is

D. why it does

解析：考查名词性从句。根据wonder可知该句为宾语从句。从句中包含了it is that的强调句，宾语从句中缺少upset的主语，故选择A