题干
He proved himself a true gentleman and the beauty of his ________ was seen at its best when he worked with others.
A：advantage
B：appearance
C：qualification
D：character
答案(点此获取答案解析）
D
，其苯环上的二溴代物有9种同分异构体，由此推断A苯环上的四溴代物的同分异构体的数目有（ ）
