I really didn’t understand made my son so sad this morning.
A. what was it
B. what it was that
C. it was what that
D. what was it that
网友回答
A. what was it
(答案→)B. what it was that
C. it was what that
D. what was it that
解析：考查强调句的特殊疑问句形式。强调句的特殊疑问句：What was it that made ….,但因为此句做understand后面的宾语从句，故用陈述语序。