问题补充：
It was not until I was injured in a car accident the real American society．
A. that I found out
B. when I found out
C. did I find out
D. that did I find out
答案：
(答案→)A. that I found out
B. when I found out
C. did I find out
D. that did I find out
解析：考查强调性句型，句型It+be+被强调的内容+that，句子意思“直到我受伤后我才发现正真的美国社会”，所以选A
