题目
-Have you ever heard of Cao Wenxuan，a writer from Jiangsu？
-Of course．______，he is a good friend of my father's．（ ）
-Of course．______，he is a good friend of my father's．（ ）
A.
I mean
B.
That is to say
C.
Above all
D.
Believe it or not
知识点：插入语章节：未标注