Question

—They will have an          holiday after the exam.
—Great.
A. one-day                                          B. eleven-day                               C. eight day’s

Answer 1

B

修饰名词表示时间可用“数词—名词”来表示，相当于形容词，an后所跟的单词第一个音应该为元音，eleven第一个音为元音，故本题选B。