问题
选择题
________ is where he gets all his money from.
A．What I can’t understand it
B．That I can’t understand
C．What I can’t understand
D．Which I can’t understand it
答案
答案：C
考查名词性从句。此题为主语从句，应用陈述句语序，句意：我不理解的就是他从哪里得到的他所有的钱。understand 后缺少宾语，所以用what,故选C。