— Do you know something about Kwanzaa?
— It is festival celebrating the culture and history of African Americans.
A. a seven-day
B. a seven-days
C. a seven day
D. seven days
网友回答
(答案→)A. a seven-day
B. a seven-days
C. a seven day
D. seven days
解析：本题考查复合形容词的用法。seven-day是复合形容词，作定语的复合形容词中的名词要用单数形式。a seven-day festival“一个七天的节日”。）